Dennison didn't find anything fascinating about religious stories, he couldn't comprehend the story behind creation and all other stories that talked about spirituality. He needed proof, he wanted to see and feel everything he was told. How can what's invisible controlled the physical?, he thought, and gradually all the interest he had about his faith began to fade away. This began when things turned apart, he was told following the faith he joined would make life easier for him, that didn't happen, instead, things became worse. Soon he had a lot of questions crossing his mind about his belief and why he had encountered a lot of challenges along the journey of his faith. There were questions he couldn't answer about his faith, instead it kept introducing a lot of questions and confusion. At the latter end, he felt becoming an atheist who believed in scientific proof was better, at least he could see and feel answers to questions that bugged his mind.
Just like the case of Dennison, a lot of people had lost faith because they couldn't find answers to problems they sought for, many who had suffered in life were moved to a point where they believed no God existed. Sometimes, people want to feel and see evidence to everything, spirituality looks like an illusion to them. A lot of people lost their faith when they felt God didn't answer their prayers, some lost their faith when they lost loved ones after praying for their recovery. Spiritual things are harder to comprehend by men, how the things of the spirit work is what can't be discerned by the flesh. This fact is what makes a lot of people lose faith. Humans are moved by what they see and scientific dimensions are what provides the satisfaction they desire.
Dennison perceived the stories that are taught in religious places to be false, his mind couldn't comprehend how one heals the sick with no medication, raises the death, rises from death after three days, is compassionate and yet allows the world to suffer. The confusion that he couldn't find answers to made him an apostate.