Authors Boa and Moody (see resource list) explain that there are essentially three possibilities as to the origin of the universe and the implications about God:

1. That the universe emerged from nothing. Little needs to be said about this notion. Nothing produces nothing. This premise is neither logical nor reasonable.
2. That the universe is eternal. There are three strong scientific reasons why the universe is not eternal: (a) the big bang theory, (b) the abundance of hydrogen, and (c) the irreversible decay of the universe.
   1. The discovery by Edwin Hubble that the universe appears to be uniformly expanding in all directions leads to the conclusion that the universe had a beginning. The Big Bang theory is not merely a proposition that matter expanded from an infinitely small position. It is the proposition that the universe had an absolute beginning—that before this event neither space nor time themselves existed at all.
   2. Hydrogen is continually being converted into helium through the process of nuclear fusion. This process is irreversible, so the abundance of hydrogen in the cosmos belies the notion of an eternal universe.
   3. The second law of thermodynamics says that while the total amount of energy remains constant (the first law), the availability of usable energy in the universe is constantly declining (the second law). Apart from the intervention of a supernatural agent (God), the stars would have burned out and the universe would have run down like a clock with no one to wind it back up. The logical conclusion is that it cannot be true that an infinite amount of time has passed because the universe would have reached a cold and lifeless state of absolute equilibrium.
3. That the universe was created by an eternal being. By process of elimination, the existence of an omnipotent God is the most reasonable conclusion for origin.

   The skeptic sometimes asks, "Well, then, who created God?" The answer is that no one created God, as he is eternal. A rule of logic states that every effect must have an antecedent cause. But God is not an effect; rather he is a cause. The logic here is simple but compelling. Since something exists, and since something cannot arise from nothing—and further that the universe itself is not eternal—something outside of the universe must be eternal. An infinite creator God must be that something. Time and space had a beginning, but God exists outside of time and space.
   Common sense reaches the same conclusion. One can prove with 100% certainty—without calling on faith or the Bible—that God exists. There is evidence of intelligent design all around us. If one sees a bird's nest, he concludes that a bird made it. If one sees a computer, he must acknowledge the evidence of an intelligent computer designer. A painting proves that there is a painter. The fact of creation proves a creator.
   There are numerous other scientific evidences for the existence of God. Even non-Christian Stephen Hawking, considered the best-known scientist since Albert Einstein, acknowledges "...the universe and the laws of physics seem to have been specifically designed for us. If any one of about 40 physical qualities had more than slightly different values, life as we know it could not exist: Either atoms would not be stable, or they wouldn't combine into molecules, or the stars wouldn't form the heavier elements, or the universe would collapse before life could develop, and so on...." (Austin American-Statesman, October 19, 1997. See also Walter Bradley video, in resource list.) We submit that the laws of physics could only have come from an omnipotent and rational God.
   Another convincing argument for God's existence is the irreducible complexity of biological systems. We address this in detail in another place on our website: Origins and Silly Putty. The advancement in scientific knowledge in this area is a major reason given by famous philosopher Anthony Flew for abandoning his atheism.
   There are other arguments for the existence of God. One of these is called the "moral argument." Let's consider this logic: (1)If God did not exist, there would be no objective moral standards. (2)Objective moral standards do exist. (3)Therefore God exists.
   Dostoevsky is credited with saying that "Without God, everything is permitted." So without God, doing something immoral would be an illusion—even nonsense, or something merely unfashionable. Atheists cannot escape the problem that without God, whoever has the most political power determines what is moral. (See also Why Believe in Moral Absolutes.)
   This line of reasoning not only points to the existence of God, it begins to explain who God is, that is, what attributes God has. We can begin to see that God is not some evil monster, but rather is a loving and rational God, consistent with the God of the Bible.
   The evidence for God is so compelling, that one must override his senses to deny Him. A thinking person who denies God must do so on the basis of preferring to believe there is no God in order to try to escape His judgment, thus irrationally seeking autonomy. Our challenge to the skeptic: At some point you must be willing to rationally consider the evidence and honestly seek with an open mind details about the God who made you.

   A book that we highly recommend on this subject is I Don't Have Enough FAITH to Be an ATHEIST, by Norman L. Geisler and Frank Turek. A smaller book is former atheist C. S. Lewis' Mere Christianity. This book has convinced many of the truth of Christianity. It is a great book to give out to friends.