I just read an article in the Deseret News about a fireside that Elder Ballard gave. In it, he mentioned that he spoke with a guy that was losing his testimony after reading anti-mormon literature. Elder Ballard asked him how much he was reading the Book of Mormon and he replied that he hadn't read it in a while. After 10 days of reading every day, he no longer had any doubts. Elder Ballard said "Give the Lord equal time."