No one could have been as much against Christianity as Saul was, and no one could be more for Christianity than Paul was.
The intensity of his feelings against and then for Christianity both marked him as a true Greek. We cannot overestimate the role that the typically Greek mind played in our beliefs. When Jesus quoted the Old Testament he used not the Hebrew but the Greek wording of it.
Every book of the New Testament was not only written in the Greek language, but it also expressed the Greek way of thinking and feeling.
That mind set was fixed by Socrates four centuries before Christ. At a time when the whole world was worshipping idols, Socrates firmly stated that the prime duty in life for each of us was to seek the truth. For him, God and Truth were the same thing. He accepted a death verdict rather that acknowledge the existence of the gods of ancient Greece.
When John wrote his Gospel at the end of the First Century most of the non-Christian Greek population believed only in something like our Mother Nature. Their name for it was simply “the Word.” So when John opened his Gospel with “In the beginning was the Word, and the Word was God” he was agreeing with those Greeks. He was saying that God pervades the whole world.