Both Mormonism and Christianity talk about having faith in Jesus. But, as with so many words and phrases, each means something differently by that.
James E. Talmage, who was an LDS apostle, defined faith this way: “Primarily, and in a theological sense, we are considering faith as a living, inspiring confidence in God, and an acceptance of His will as our law, and of His words as our guide in life.” Apostle Joseph B. Wirthlin put it this way: “We each should develop the faith of Nephi to do the things the Lord has commanded [see 1 Ne. 3:7] knowing that all commandments are given for our good.”
When Christians talk about faith in Jesus, however, they are not talking about accepting His will as our law or even His words as our guide in life. The first and primary things Christians think about when faith comes up are not Jesus’ words but his works. To Christians, having faith in Jesus means trusting that what Jesus did he did for us and because Jesus has done those things, we are already acceptable to God. So much so that faith in Jesus, for Christians, includes the thought of abandoning any reliance on our own works. But note that any mention of Jesus’ works for us is completely absent in James E. Talmage’s words – even though he is describing faith “primarily”.
Although both Mormonism and Christianity talk about having faith in Jesus, they have two different objects in which they place their faith. In order to understand each other and not talk past each other, it is important to see this difference. It is not enough to agree that both talk about having faith in Jesus. The telling question is: faith in Jesus’ what?