Behold I will send you Elijah the prophet
before the coming of the great and dreadful day of the LORD.
And he will turn the hearts of the fathers to the children,
and the hearts of the children to their fathers,
lest I come
and strike the earth with a curse.
Malachi 4:5, 6
For all the prophets and the law prophesied until John.
And if you are willing to receive it,
he is Elijah who is to come.
Matthew 11:13, 14