Faith & Reason Ministries

Science and Christianity: Chapter 5. Who is Man, Really?

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Science and Christianity

by John D. Callahan

Third Edition

Copyright © 1985, 1986, 1998 by John D. Callahan

All Biblical quotations are from the Good News translations (3rd or 4th editions) by the American Bible Society.

ISBN 0-9615767-0-7 (2nd edition)
Library of Congress Catalog Card Number: 85-91519 (2nd edition)


Now that we have a good model for the nature of the universe in both a physical and spiritual sense, and because we now know man's physical position in the universe, we can explore man's true identity spiritually. Some theologians, without a clear picture of the universe, have conceived man to be God's highest ultimate creation and the center and meaning of all life. They thought of angels as "ministering spirits" (Heb. 1:14) created to serve man. How shocking it is to realize that this is not the case at all. A man's average life span is but 70 years, and we are evolved from apes. The universe, on the other hand, and the great spiritual beings in it have existed for billions of years. The number of these spiritual beings may be unimaginable, and their powers affect the fundamental laws of the entire universe. For they were created before it. Man is caught in the middle of a titanic spiritual battle which rages across billions of light-years in distant galaxies from one corner of the universe to the other. Satan and demons war against God and the angels as He works to create and do good.

To further put things in their proper place, let us consider the possibility of intelligent life, similar to man, existing elsewhere in the universe. Although there have been many sightings of UFO's and reports of "close encounters," no real "hard" evidence such as an alien book or machine or corpse has ever been found. It's a big universe and man has been on the scene only a very short time. The universe could be full of intelligent life which we are not directly aware of. Rather than trying to prove that we have been visited by aliens, let's consider another approach. Let's try to predict the probability, based on what we understand, of intelligent life developing elsewhere in the universe.

It is reasonable to suppose that if the conditions which gave rise to life upon the Earth are duplicated in other parts of the universe then life will have a high probability of developing there also. The first question to ask is: how common is our star the sun? Well our sun is "normal" and a little hotter than the average star; it has a lifetime of around 10 billion years. Stars of this nature make up about 2% of the stars in the Milky Way Galaxy. Our sun has the further distinction of being a "single" star. That is, it has no companion star which orbits it. At least half the stars in the Galaxy are not "single" but rather "double" or "triple" stars. Therefore approximately 1% of the stars in the Galaxy are like the sun if we add this constraint.

In addition, the sun is 5 billion years old (the Galaxy is 10 billion years old) and formed in the spiral arms of the Galaxy, as opposed to the central regions. This latter constraint might make a difference in chemical composition. Now if we assume a uniform rate of formation of the stars and only consider stars between 4 and 9 billion years old, this reduces our 1% figure to .5%. Of these, at least half are in the spiral arms, so we are left with a rough figure of .25%. In other words, of the stars in our Galaxy, the Milky Way, approximately 1/4 of 1% are very similar to the sun. Since the Milky Way consists of around 100 billion stars, it is safe to say that there are 250 million stars like the sun and capable of supporting intelligent life.

Next we should ask the following. Of the stars capable of supporting intelligent life, how many have planets similar to Earth? Looking at our own solar system, we note that it consists of 9 planets spaced fairly regularly from very close to the sun (Mercury) to very far away (Pluto). This implies that the sun and planets condensed from an interstellar cloud of dust and gas. The cloud flattened into a disk while rotating, and the sun and planets formed from the material. Such a process is highly likely, given our understanding of physics and astronomy, and is probably the norm rather than the exception. We also know, from careful studies, that nearby stars, particularly Barnard's Star, seem to have planets. Getting back to our solar system, Venus and Mars are similar to the Earth in many ways, and these planets were almost "life supporting" like the Earth. Mars in particular once had great rivers of running water on its surface. It is, therefore, reasonable to assume that of the stars capable of supporting intelligent life, many also have planets suitable for life.

As a rough, conservative guess, let us say there are 100 million such planets in our Galaxy. Now of these, on how many has any kind of life actually arisen? Well we know from laboratory experiments that the molecules necessary for life readily form, and even in interstellar space, complex molecules containing half a dozen or more atoms have been discovered. Simple life, in the form of reproducing molecules, would most likely arise on any planet similar to the Earth revolving around a star similar to the sun.

The evolution now from reproducing molecules to intelligent creatures would slowly begin. It seems reasonable that life would eventually overrun a planet and develop into all kinds of forms, just as life has on Earth. In particular, trees and the creatures which live in them would develop. Certain of these creatures would doubtless become limb swinging apes just as on our planet. Some of these apes would eventually readapt to ground living developing large brains and erect posture. These intelligent creatures would be similar to us but truly beings from another world. They might have all kinds of modifications to the basic humanoid appearance, such as different heights, weights, colors and textures of hair, and relative sizes of limbs and features.

Now barring catastrophic events, such as the splitting apart of a planet by a huge meteor or the death of all life due to the explosion of a nearby star, it is likely that of the planets capable of supporting intelligent life, a significant fraction have indeed developed it. This is probably the case, for we know from our knowledge of astronomy that the catastrophic events, though not rare, are not frequent either. Also we have no reason to suppose that we will find any "unknown" factor which will grossly diminish the number of intelligent civilizations. Still, the probability of developing intelligent life is bound to be smaller than simple life. However, the probability is most likely not grossly smaller. This is, again, truly amazing and means that there are most likely millions of other intelligent races in our Galaxy alone.

Let's be conservative and say, for estimation purposes, that out of the 100 million planets we guess are capable of developing intelligent life, only 1 million actually developed an intelligent civilization. We know that there are also at least 100 billion other galaxies in the universe. This means that there are approximately 100,000 trillion intelligent civilizations similar to our own in the universe. Given that there are very roughly a billion creatures per civilization, as on our Earth, then there are 100,000 billion trillion intelligent creatures like ourselves in the universe! Moreover, new creatures with intelligence will continue to arise in the future as the eons pass.

Many scientists believe that the above scenario is too optimistic, given the great complexity of biology. They believe that the conditions suitable for intelligent life occur much less frequently. However, even if circumstances must be "just right" for intelligent life to develop, there are still so many stars and galaxies in the universe that many intelligent societies would probably exist. For instance, if instead of a million intelligent civilizations per galaxy (as given above), there is only one intelligent civilization per million galaxies (this reduces the probability by a trillion), then there would still be 100,000 intelligent civilizations in the universe! By the way, if there is only one intelligent civilization per many, many galaxies then "close encounters" between different intelligent civilizations would almost never occur. This is because the closest galaxies are still separated by hundreds of thousands of light-years, and only the most incredibly advanced civilization could make such a journey and then find another intelligent civilization. For instance, if there is one intelligent civilization per one hundred galaxies, then any one civilization would probably never come in contact with another, but there would be roughly a billion intelligent civilizations in the universe! However, again, unless intelligent life is very sensitive to biological factors being "just right," there are probably many, many intelligent civilizations per galaxy.

To complete the argument for the existence of intelligent life in the universe other than man, let us take the above line of thought one step further. Enrico Fermi once proposed the famous question, "Where are they?", in reference to extraterrestrial intelligence (ETI). He was implying that if extraterrestrials existed, then we should be visited by them. This is a logical conclusion assuming a certain population of intelligent life within our Galaxy, because a number of these civilizations would have existed much longer than our own and would have overcome the immense difficulties of interstellar space travel. Since we do not have "hard evidence" that we are being visited, the conclusion is that ETIs must not exist.

However, since we exist, we know it is possible for the universe to produce intelligent life, but how probable is our existence? Although we know that there are many stars like our sun with probable planetary systems similar to our solar system, some astronomers argue that we are unique in the universe, requiring just the right galaxy, supernova rate, star, moon, magnetic field, thickness of crust, quantity of greenhouse gases, etc. Other astronomers believe our own Galaxy is full of intelligent life, despite Fermi's question. There is no consensus among astronomers, biologist, and other scientists regarding the answer to this question, and it may be a long time before there is.

My answer is "here we are" implying that since we exist, there are (or will be) most likely other intelligent life forms in the universe (if not the Galaxy). If we make the simple and reasonable assumption that we are not a fluke, then our universe has -- at the very least -- a significant probability (say 50%) of producing at least one intelligent life form (us) in 10 billion years. If this is the case, then there is a good chance that there is at least one or a handful of other intelligent civilization in the universe right now or will evolve in the future.

The above argument is consistent with Occam's razor: accept the simplest explanation with the fewest assumptions and reject more fantastic and convoluted explanations. Since we exist, the simplest explanation is that the entire universe had a reasonable probability of producing at least one intelligent life form: us. Remember the universe is a big place -- much bigger than our Galaxy. The universe consists of at least 100 billion galaxies. Further, it is going to exist for a long, long time before entropy (like the slow running down of a clock) or collapse overtake it, and therefore life will continue to evolve over the eons in the universe's vastness.

Additionally, it is not inconceivable that our own race may perish in a thousand or million or billion years, and another intelligent life form evolves on this planet before our sun dies (another 5 billion years).

Let us increase the probability somewhat and suppose (purely hypothetical) that there is a 50% chance of life evolving once every 5 billion years per 100 million galaxies. This doesn't sound like much. However, when we take into account the size of the universe, it translates into hundreds of ETIs right now, and many tens of thousands over the lifetime of the universe. Further, no one ETI would ever contact another.

One footnote should be made. While the majority of scientists would say we have no "hard evidence" of ETIs, I am not as convinced as I once was that we have not already been visited. The reports of abductions, etc. cannot, in my mind, be 100% dismissed as fantasy. Although this may turn out to be the case.

God is working in the lives of these intelligent creatures also, just as He works with us. Jesus may have come to countless planets throughout the universe in the form of the intelligent life which lives there. Note in the following quote of Jesus that He uses the article "this" instead of "the" implying that our world is not unique. "Jesus answered, 'You belong to this world here below, but I come from above. You are from this world, but I am not from this world' " (John 8:23). Of course the tremendous wicked spiritual forces, which hinder God's work on this planet, are also at work on other planets. The struggle to find God would doubtless be difficult for other intelligent civilizations just as it is difficult for us. However, it is not hard to suppose that some societies might do better than others. Some might be very close to God while others are very far away.

So in the midst of this great turmoil, man, as on other planets which contain intelligent life, is evolved from the more fundamental life forms of his planet. All of which are incapable of understanding any significant spiritual meaning to the universe. Man on the other hand, while he is far below the angels, is able to understand something of what is going on. He uses his mind to understand the universe in both a physical and spiritual sense. He constructs models, containing facts and theories about the universe, which he has arrived at through observation and experimentation. He also understands the universe through direct revelation from God. The models are only so good, though, and man continues to learn about the universe. Knowing how the universe works helps man to better function in it. For example, understanding the laws of medicine allowed Dr. Jonas Salk to discover a vaccine for polio. Knowing something about the laws of aerodynamics helped the Wright brothers to invent the airplane. And correctly understanding spiritual laws can even bring eternal life to men.

The mission of Jesus Christ, God in the flesh, upon the Earth was to reveal God to men and provide a way for us to receive eternal life. God is good, the creator, and infinite. He cares about all life everywhere. He is doing all that He can for us. However, He is being bitterly opposed by great supernatural powers, who He created and who turned from Him in the beginning in pride. That God chose to work in human history the way that He did is the most He could do. We must trust Him in this. It is true that many innocent people will never hear about Jesus, such as those who lived before Him (actually a small percentage given the population explosion) and those who live in remote parts of the world. But, again, God has done all He can do. If the innocent are lost, it is the fault of Satan, demons, and other men, but not God. Though He is infinite, God will not bind all evil until Judgment Day. He has granted the responsibility of life and free will, even if it is against His own will, and He must work within this framework.

We are not completely sure of what Jesus said. Yet the basic meaning of His words is consistent as He Himself speaks many times throughout the Gospels. Also the message is supported by all the other New Testament writers. Perhaps Jesus' clearest and most interesting explanation of man's relationship to God is found in the third chapter of the Gospel of John. Here a well-known and respected religious leader, Nicodemus, comes at night to visit Jesus. Nicodemus was profoundly impressed by the ministry of Jesus. Yet most other religious leaders of the day did not accept Jesus; this is why Nicodemus came in secret at night.

When Nicodemus confronts Jesus he says, "Rabbi, we know that you are a teacher sent by God. No one could perform the miracles you are doing unless God were with him" (John 3:2). Remember, as was discussed in chapter 3, Jesus had incredible powers over the physical and spiritual universe, including power over death itself. But just as today, most men, even in the face of these glaring realities, were unable or unwilling to face up to the implications of Jesus' life. Nicodemus was not one of them, for he came to learn about Jesus.

Now Jesus answers Nicodemus with a statement which is fundamental to man's relationship to God and also a problem in Nicodemus' life: "Jesus answered, 'I am telling you the truth: no one can see the Kingdom of God unless he is born again' " (John 3:3). Here Jesus sets the tone of the conversation, that is, salvation. Nicodemus knows that Jesus is, of course, not speaking literally. Yet he does not catch the true spiritual implications in Jesus' words. Nicodemus asks a question designed to set himself up as the judge of Jesus' teaching: " 'How can a grown man be born again?' Nicodemus asked. 'He certainly cannot enter his mother's womb and be born a second time!' " (John 3:4).

" 'I am telling you the truth,' replied Jesus, 'that no one can enter the Kingdom of God unless he is born of water and the Spirit. A person is born physically of human parents, but he is born spiritually of the Spirit. Do not be surprised because I tell you that you must all be born again. The wind blows wherever it wishes; you hear the sound it makes, but you do not know where it comes from or where it is going. It is like that with everyone who is born of the Spirit' " (John 3:5-8).

Nicodemus can no longer hide his ignorance. He replies, "How can this be?" (John 3:9). While Nicodemus did not understand, we can be fairly certain today of what Jesus was saying. When He said, "born of water and the Spirit" (John 3:5), the water referred to the baptism of John the Baptist. John's message was one of repentance. He urged the people to turn from their sins. At the same time, John acknowledged his role, mentioned in the scriptures, as the precursor to Jesus. About Jesus and His work John states, "I baptize you with water to show that you have repented, but the one who will come after me will baptize you with the Holy Spirit and fire. He is much greater than I am; and I am not good enough even to carry his sandals" (Matt. 3:11). "This is the one I was talking about when I said, 'A man is coming after me, but he is greater than I am, because he existed before I was born' " (John 1:30). This last statement points to Jesus' divinity, because John was actually born approximately a year before Jesus.

John referred to a baptism by Jesus, of the Spirit, and this is of course what Jesus Himself is also referring to. The Spirit is the Spirit of God, and Jesus likens Him to the wind in the physical world. We clearly see the effects of the wind in the physical world. Yet it is invisible and we do not understand its origin or destination completely. The fact that wind exists cannot be questioned. In the same way, those "born again" are able to perceive the effects of the Spirit of God. His (The Spirit's) effects are clearly seen in the world and the lives of men. Yet He is invisible and we do not understand His origin or destiny completely. The fact that the Spirit exists cannot be questioned.

The whole implication here concerning the believer's baptism by the Spirit is his (the believer's) personal awareness of God. To the true believer God is not some far off entity in the sky who we read about in books and try to please in our own human wisdom. Rather, the existence, presence, and actions of God are directly perceived by the believer. This implies a personal union, friendship, and dependance by the believer on God. Indeed there are other scriptures which indicate that the true believer is to be in direct communion with not only the Spirit but also the Father and Son (for example see John 14:23 and John 17:21).

Getting back to the dialogue between Jesus and Nicodemus, Jesus seems to react with indignation at Nicodemus' question: "How can this be?" (John 3:9). Jesus says, "You are a great teacher in Israel, and you don't know this?" (John 3:10). Here we see a great problem with the world. We have a man, Nicodemus, who is a priest, highly educated, a leader of the people, and even sincere. Yet he does not even understand the basics of man's relationship to God! However, this is not really surprising, considering what we now know about the universe and man's place in it.

Jesus now proceeds to throw more light on the issue: "I am telling you the truth: we speak of what we know and report what we have seen, yet none of you is willing to accept our message. You do not believe me when I tell you about the things of this world [note Jesus again uses "this" instead of "the"]; how will you ever believe me, then, when I tell you about the things of heaven? And no one has ever gone up to heaven except the Son of Man, who came down from heaven" (John 3:11-13).

"As Moses lifted up the bronze snake on a pole in the desert, in the same way the Son of Man must be lifted up, so that everyone who believes in him may have eternal life" (John 3:14-15). Here Jesus refers to an incident which befell the Jewish people, while they were wandering in the desert. Because of their disobedience, God sent poisonous snakes which bit the people. However, God instructed Moses to make a bronze snake and put it on a pole. Any Israelite who would turn from his or her sin and as a sign of repentance look at the bronze snake would be spared from the snakes. Jesus uses this as an analogy to His mission upon the Earth. We are all bound, to some degree, by sin and disobedience to God as a natural consequence of living under the present conditions (remember, in John 14:30, Jesus called the Devil "the ruler of this world"). This causes separation from God. However, we are largely innocent victims of the great spiritual war which is raging across the universe. God has provided a way for us to be right with Him by sending His only Son, Jesus Christ, into the world to die on the cross and pay the penalty for our sin. Anyone who will turn from his sin looking to and believing in Jesus will be saved. True repentance will bring with it a personal relationship and friendship with God, who will give the believer the understanding and strength to begin to overcome sin in his life. The believer will never obtain perfection in this life, but he will always be saved as long as he is "born of water and the Spirit" (John 3:5).

Jesus continues, "For God loved the world so much that he gave his only Son, so that everyone who believes in him may not die but have eternal life. For God did not send his Son into the world to be its judge, but to be its savior. Whoever believes in the Son is not judged; but whoever does not believe has already been judged, because he has not believed in God's only Son. This is how the judgment works: the light has come into the world, but people love the darkness rather than the light, because they do evil things. Anyone who does evil things hates the light and will not come to the light, because he does not want his evil deeds to be shown up. But whoever does what is true comes to the light, in order that the light may show that he did his works in obedience to God" (John 3:16-21).

This then is the solution to man's existence. Despite all the ironies and paradoxes of this life, true belief in Jesus brings eternal life. We may not understand it all; in fact we probably understand only a little. We know a little about the universe, man, and the great complexity involved with both. We know that the universe is much more vast and profound than we ever imagined, and we are caught, as it were, in a great spiritual conflict. However, we can be even more sure that Jesus is a historical figure and divine. He alone gives life everlasting and certain meaning. He alone was God incarnate and His words have changed the course of history. As He said, "Heaven and Earth will pass away, but my words will never pass away" (Mark 13:31).


Make a selection

  • Introduction & Chapter 1. Is the Bible Perfect?

  • Chapter 2. A Lesson in Astronomy

  • Chapter 3. Who Are God and Satan, Really?

  • Chapter 4. A Lesson in Life Upon the Earth

  • Chapter 5. Who is Man, Really?

  • Summary & About the Author

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