Dave grew up in a Jewish family that valued education, so he grew up reading and learning a lot about religion, specifically Greek mythology. He saw the claims of Jesus as no different than anything he read in his mythology books.
Learning about family members who perished in the Holocaust caused Dave to pursue a strong Jewish identity. He was committed to Jewish life and the Hebrew Scriptures.
The loss of his grandmother caused Dave a lot of pain. In fact, her death was sudden and tragic, and it forced Dave to question a lot of things in life at an early age. Struggling with these questions for years left Dave empty and depressed. It was through a series of supernatural events that the Messiah of Israel, Jesus, was revealed to him.