fiona84,
I really like some of the things prisonchaplain has said concerning belief in God. Our message to the world is the following:
1) There is a God and our spirits are his children.
2) Jesus of Nazarath is the Christ, the Son of God, and by his atonement he has overcome the effects of death for all, and the effects of sin for the faithful.
3) Joseph Smith is a true prophet of God, and through living prophets today God reveals his plan to his children as he did anciently.
4) The Book of Mormon is the word of God, and is evidence that Joseph Smith is a prophet of God.
5) The Church of Jesus Christ of Latter-day Saints is the true Church of Jesus Christ, and the only Church where the priesthood of God is found on the earth.
We assert that in order for a person to know for themselves that our message is true, and from God, God himself must reveal it to that person. The Book of Mormon plays a key role in helping individuals receive this revelation. The Book of Mormon was written by ancient prophets who saw our day, and knew our situation. It was intended as another witness of Jesus Christ and of his everlasting Gospel. By exercising faith in Christ and reading, pondering, and praying about the Book of Mormon, a person can gain a witness by the power of the Holy Ghost that it is true.
When you know the Book of Mormon is true, it follows that Joseph Smith was a true prophet, because he claims that he translated the Book of Mormon by the gift and power of God. Which means in turn that the Gospel and Church of Jesus Christ, as restored through the prophet Joseph Smith, are true as well.
I am glad to hear that he is taking this issue to heart and experimenting with faith, and prayer. That is the best thing he can do to gain an answer from God. I would encourage serious reading and pondering about the Book of Mormon as well. Make no mistake about it, there will be a trial of faith before the answer comes, but it will come to those who are true seekers of truth. It's a matter of faith.

Praying is an act of faith, and by doing it, even if our faith in God is weak, our faith will increase. It is a wonderful process. Here is a favorite scripture of mine from the Book of Mormon for him to ponder:
And now, I, Moroni, would speak somewhat concerning these things; I would show unto the world that faith is things which are hoped for and not seen; wherefore, dispute not because ye see not, for ye receive no witness until after the trial of your faith. (Ether 12:6)
I personally testify that Jesus is the Christ. I have applied his atonement in my life and tasted of the sweetness of his gospel. I have received a remission of my sins on more than one occasion, and I know the way to retain that remission. It is through faith in Jesus Christ and his atonement, repentance, and through making and keeping sacred covenants with the Lord. I testify that the Book of Mormon is true, and it is the word of God. I have received a witness by the power of the Holy Ghost after a trial of my faith, and I now know it to be true.
Sincerely,
Vanhin