The Bible never tries to prove that there is a God, but in the Bible the living God speaks to us. He tells us of Himself and of how we may know Him and enjoy His presence with us and in us.
Those who become Christians are almost always converted through hearing God speak to them through the message of the Bible, and then responding to Him.
The intelligent Bible student rightly argues that one truth cannot contradict another. If we accept the Bible as true, and hold that God created all things, what are we to think of a scientific explanation of the universe that has no place for God?
It is obviously impossible to deal with the first five books of the Bible here, so the author has chosen Genesis, in order to show that its form and contents make it perfectly reasonable to accept that Moses was the author.