As a student in physical chemistry, Dr. Francis Collins was an atheist. He did not see any reason to prove the existance of any truths at all outside of the fields of mathematics, physics and chemistry. After he realized that there was a big movement in molecular biology and genetics, he changed his field of study to genetics and transferred from Yale to the University of North Carolina (after graduating from Yale with a Ph.D in physical chemistry). While at UNC, Collins encountered many patients who were on their death beds, one of whom asked him a question that got him thinking for the rest of his life.
The patient asked, "What do you believe, doctor?" This simple question triggered numerous other questions in Collins' mind. "What is the meaning of life?" "Why am I here?" "If the universe had a beginning, who created it?" "What happens after we die?" These are just a few of the questions that arose in Collins as he tried to figure out what he believed.
"I had always assumed that faith was based on purely emotional and irrational arguments, and was astounded to discover, initially in the writings of the Oxford scholar C.S. Lewis and subsequently from many other sources, that one could build a very strong case for the plausibility of the existence of God on purely rational grounds." - Dr. Francis Collins
When Collins was 27, in the effort to learn more about God's character, he learned about Jesus Christ. Collins said that "[He] was a person with remarkably strong historical evidence of his life, who made astounding statements about loving your neighbor, and whose claims about being God's son seemed to demand a decision about whether he was deluded or the real thing." After about two years of debating whether or not Jesus was truly God, Collins finally became a follower of Jesus.
Collins has been questioned many times about how he can believe in God and also be a scientist. They questioners ask him if the two views are too conflicting. Collins responds by telling them that it is not overwhelming at all, but that he has found a wonderful balance between the truths of science and faith. He says that "by investigating God's majestic and awesome creation, science can actually be a means of worship."