testimony

faith brings us testimonies, and testimonies strengthen our faith.
This cycle is significantly important for a latter-day saint,
as testimonies are the weapons for us to fight again trials or temptations.

in D&C 138:12, "And there were gathered together in one place an innumerable company of the spirits of the just, who had been faithful in the testimony of Jesus while they lived in mortality",
it states the importance and relation of faith and testimony.

in D&C 76:22, "And now, after the many testimonies which have been given of him, this is the testimony, last of all, which we give of him: That he lives! "
i personally know that Jesus is the Christ, I know He lives,
and because of His atonement, our sins are forgiven,
and we have the chance to go back to Father's presence.