Someone doubting the truth of the torah should spend time with someone from Aish or the like. They have both rational reasons for emunah (toras emes) and the emotional experiences (toras chaim) that combine to create a powerful experience.
On a personal note, I was saved by a gadol giving what was also rational advice. I was very young when I became extremely ill. We went to specialists and they couldn’t figure it out. A friend went to the lubavitcher rebbe and gave him my name and situation. He recommended that we check my father’s tfillin and that we try a pediatrician – maybe it was something we overlooked. He was right on both counts, and I’m alive today thanks to his spiritual and practical advice – and the incredible diagnostic skills of the pediatrician who caught what top notch specialists missed.