Joseph Smith taught that three things "are necessary in order that any rational and intelligent being may exercise faith in God unto life and salvation."
-First, the idea that he actually exists.
-Secondly, a correct idea of his character, perfections, and attributes.
-Thirdly, an actual knowledge that the course of life which he [the person] is pursuing is according to his [God's] will.
For without an acquaintance with these three important facts, the faith of every rational being must be imperfect and unproductive; but with this understanding it can become perfect and fruitful, abounding in righteousness, unto the praise and glory of God the Father, and the Lord Jesus Christ.