Joseph Smith said in the King Folette "The greatest responsibility in this world that God has laid upon us is to seek after our dead. The apostle says, “They without us cannot be made perfect”; for it is necessary that the sealing power should be in our hands to seal our children and our dead for the fulness of the dispensation of times—a dispensation to meet the promises made by Jesus Christ before the foundation of the world for the salvation of man.
Now, I will speak of them. I will meet Paul half way. I say to you, Paul, you cannot be perfect without us. It is necessary that those who are going before and those who come after us should have salvation in common with us; and thus hath God made it obligatory upon man. Hence, God said, “I will send you Elijah the prophet before the coming of the great and dreadful day of the Lord: he shall turn the heart of the fathers to the children, and the heart of the children to their fathers, lest I come and smite the earth with a curse.”

I know this is TRUE !! Tom Bassett