Can you tell me why it is that I have doubts about the truthfulness of the Book of Mormon when I read it?

Dear Gramps,
When I’m reading the Book of Mormon, I get doubts of it being true. If I read the Bible I don’t, I totally believe, I’m a member of the Mormon Church and I still believe that the Church is true. I’ve been to the temple and have felt the spirit. I’ve had countless revelations, but why do I doubt so much when I’ve got the evidence in front of me? I don’t want to doubt and I try hard not to.
Andy

Dear Andy,
A testimony of the truthfulness of the Book of Mormon is a gift from God, as is the testimony of all the other truths of the gospel. If the Lord were to touch your heart with a believing spirit, you would have your testimony.
Here is what I would suggest. Start from the first of the book once again. When you read the book this time, do so with a prayerful heart. Thus, every time you turn a page, stop and ask the Lord to reveal to you that the Book of Mormon is indeed the word of God. Any passage that brings any doubt of authenticity to your mind, mark it in red. Before continuing to the next page, prayerfully study the passage in question, looking up the footnotes, as appropriate. You would also do well to compare the passage with related verses found in the other scriptures. I have the impression that if you follow this procedure, before you read to the end of the Book of Mormon, the Lord will have answered your prayer.
Gramps