General Latter-day Saint
Malachi’s Elijah promise as Moroni gives it (D&C 2)
1 Behold, I will reveal unto you the Priesthood, by the hand of Elijah the prophet, before the coming of the great and dreadful day of the Lord. 2 And he shall plant in the hearts of the children the promises made to the fathers, and the hearts of the children shall turn to their fathers. 3 If it were not so, the whole earth would be utterly wasted at his coming.