Malachi 4:5

And he shall go before him in the spirit and power of Elias, to turn the hearts of the fathers to the children, and the disobedient to the wisdom of the just; to make ready a people prepared for the Lord.

And his disciples asked him, saying, Why then say the scribes that Elias must first come? And Jesus answered and said unto them, Elias truly shall first come, and restore all things. But I say unto you, That Elias is come already, and they knew him not, but have done unto him whatsoever they listed. Likewise shall also the Son of man suffer of them. Then the disciples understood that he spake unto them of John the Baptist.

And they asked him, saying, Why say the scribes that Elias must first come? And he answered and told them, Elias verily cometh first, and restoreth all things; and how it is written of the Son of man, that he must suffer many things, and be set at nought. But I say unto you, That Elias is indeed come, and they have done unto him whatsoever they listed, as it is written of him.

For all the prophets and the law prophesied until John. And if ye will receive it, this is Elias, which was for to come.

Behold, I will send my messenger, and he shall prepare the way before me: and the Lord, whom ye seek, shall suddenly come to his temple, even the messenger of the covenant, whom ye delight in: behold, he shall come, saith the Lord of hosts.

The voice of him that crieth in the wilderness, Prepare ye the way of the Lord, make straight in the desert a highway for our God.

The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the Lord come.

And they asked him, What then? Art thou Elias? And he saith, I am not. Art thou that prophet? And he answered, No.

For, behold, the day cometh, that shall burn as an oven; and all the proud, yea, and all that do wickedly, shall be stubble: and the day that cometh shall burn them up, saith the Lord of hosts, that it shall leave them neither root nor branch.

For the great day of his wrath is come; and who shall be able to stand?

But what went ye out for to see? A prophet? Yea, I say unto you, and much more than a prophet. This is he, of whom it is written, Behold, I send my messenger before thy face, which shall prepare thy way before thee. For I say unto you, Among those that are born of women there is not a greater prophet than John the Baptist: but he that is least in the kingdom of God is greater than he.

And they asked him, and said unto him, Why baptizest thou then, if thou be not that Christ, nor Elias, neither that prophet?

And, behold, there talked with him two men, which were Moses and Elias:

Some of them that stood there, when they heard that, said, This man calleth for Elias. And straightway one of them ran, and took a spunge, and filled it with vinegar, and put it on a reed, and gave him to drink. The rest said, Let be, let us see whether Elias will come to save him.

And I will shew wonders in heaven above, and signs in the earth beneath; blood, and fire, and vapour of smoke: The sun shall be turned into darkness, and the moon into blood, before that great and notable day of the Lord come: