The Book of Mormon says, IIRC 2 Ne 9: "Wo unto the liar, for he shall be thrust down to hell." This life isn't always fair, but we can trust Him to get it right in the end -- the important thing is that we are honest and never stop humbly trying to do what is right. I have learned we really can be OK.

Edit: Which doesn't make it easy or less real -- but knowing it really helps me.