I got a letter from my son (serving a Mormon mission in the US) which was very good actually on this subject. He was visiting a fellow who had lost his faith and felt as though almost any religion can make a convincing case for their teachings:
Sure. All Religions teach good things and there are similarities in every religion. Every religion teaches the truth and I’m sure that if you read all of their literature and do all of what they ask, you can trick yourself into believing it. Faith is a real power. In the scriptures you can read that in a certain area Christ could do no miracles because of the lack of belief there (I need to get the reference for that one still), but when you believe in Christ and do what he asks you will not be disappointed. I opened up to 1st Kings chapter 18 and read him the awesome words of Elijah (21) “How long halt ye between two opinions? If the Lord be God, follow him; but if Baal, then follow him” and showed him all of the story and how sure, the Priests of Baal believed fervently in Baal but their faith was worthless because Baal is an idol and not a God of Miracles. Elijah calls upon the true God and he lights the altar and shows forth God’s miraculous power.
Then the spirit took over and told me what to share. I told him that the God of Miracles is God the father, Jesus Christ and the holy Ghost and that only through Jesus Christ can one work miracles. I told him of my experience with anti’s and how reading the Book of Mormon swept most of my concerns clean away. I shared Hel. 3:29-30 which has become another one of my favorite scriptures
“Yea, we see that whosoever will may lay hold upon the word of God, which is quick and powerful, which shall divide asunder all the cunning and the snares and the wiles of the devil, and lead the man of Christ in a strait and narrow course across that everlasting gulf of misery which is prepared to engulf the wicked— And land their souls, yea, their immortal souls, at the right hand of God in the kingdom of heaven, to sit down with Abraham, and Isaac, and with Jacob, and with all our holy fathers, to go no more out.”
I felt prompted to tell him that Moroni’s promise is no less valid now than when he first read the Book of Mormon and that if he read it and prayed the same testimony would come back that he once had. My voice was near cracking and I ended what I said in the name of Jesus Christ and he was crying as well. He just smiled and said “hey, thanks.” We talked a little more with him and then left.
While part of me feels glad that I could reason with him, I know that after reading Helaman, it was the spirit that bore witness to him that the message was true. The spirit is real and while I’m glad I was there I know that the logic would have been nothing without the spirit to confirm to him that God is a God of miracles.