Complex sentence: It was the result of this lifelong study of the natural world and his devotion to empirical evidence that he felt atheism was the only rational deduction available in light of all evidence saying, My practice as a scientist is atheistic.
Split into simpler sentences: It was the result of this lifelong study of the natural world and his devotion to empirical evidence that he became an atheist. He felt that atheism was the only rational deduction available in light of all the evidence, saying, My practice as a scientist is atheistic.