Elijah

Old Testament prophecy 

Malachi 3:1 Behold, I will send my messenger, and he shall prepare the way before me: and the Lord, whom you seek, shall suddenly come to his temple, even the messenger of the covenant, in whom you delight: behold, he shall come, says the Lord of hosts.  

Malachi 4:5-6 Behold, I will send you Elijah the prophet before the coming of the great and dreadful day of the Lord: And 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.

New Testament fulfillment 

Matthew 11:7-15 

And as they departed, Jesus began to speak to the multitudes concerning John. 

What did you go out into the wilderness to see? A reed shaken with the wind?

But what did you go out to see? A man clothed in soft garments? They who wear soft clothing are in kings’ houses.

But what did you go out to see? A prophet? Yes, and more than a prophet.

For this is he, of whom it is written, Behold, I send my messenger before your face, which shall prepare your way before you.

Truly, among those who are born of women there has not risen one greater than John the Baptist: yet he that is least in the kingdom of heaven is greater than John.

And from the days of John the Baptist until now the kingdom of heaven suffers violence, and the violent take it by force.

For all the prophets and the law prophesied until John.

And if you will receive it, this is Elijah, who was to come.

He who has ears to hear, let him hear.
Matthew 17:10-13

(As Jesus came down the mountain with Peter, James and John after the transfiguration.)

Disciples: Why do the scribes say that Elijah must come first?

Jesus: Elijah truly shall come first and restore all things. But Elijah is already come, and they did not know him, but have done to him whatever they wanted. Likewise the Son of man shall suffer of them also.

Then the disciples understood that he spoke to them of John the Baptist.