Any discussion on biblical interpretation must consider how the Bible is interpreted internally. If the inspired word of God makes use of a particular method of interpretation consistently, that should direct how the scripture should interpreted.
Consider the following passage in Mark 9:11-13:
“And they asked Him, saying, “Why do the scribes say that Elijah must come first?” Then He answered and told them, “Indeed, Elijah is coming first and restores all things. And how is it written concerning the Son of Man, that He must suffer many things and be treated with contempt? But I say to you that Elijah has also come, and they did to him whatever they wished, as it is written of him.”” [1]
The scribes taught that Elijah would come in the timeframe of the Messiah, which the Lord Jesus confirms. However, He adds that Elijah has already come. Matthew 17:13 reveals that “Then the disciples understood that He spoke to them of John the Baptist.” [1]
How is this interpreted? The passage of the Old Testament referenced here is 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 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.” [1]
This passage is quoted before the birth of John the Baptist in Luke 1:17, “He will also go before Him in the spirit and power of Elijah, ‘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.” [1] This revelation from God declared that John would come in the “spirit and power of Elijah”, and not be Elijah himself.
Matthew 11:13-15 “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. He who has ears to hear, let him hear!” [1] The Lord Jesus, Who cannot lie, declares that John would fulfill the prophecy, but only if they were willing to receive. The passage in Malachi appears to very clearly state that the Lord will send Elijah the prophet, and yet the Lord Jesus states of John that “he is Elijah who is to come”. John’s own words in John 1:21 declare that he understood that he was not Elijah, “And they asked him, ‘What then? Are you Elijah?’ He said, ‘I am not.’” [1]
How is this interpreted?
Letterism is immediately out, else John would have to be Elijah.
Literal interpretation is quite possible, if John is a type of Elijah (more on typology later), or if Malachi 4 is a metaphor and the one prophesied is similar to Elijah in ministry and character.
Allegorical interpretation is a possibility as well, though the only detail not explicitly literal is the identification of Elijah. The rest of the prophecy makes good sense without needing to seek a deeper meaning.
Overall, how this prophecy is viewed in the New Testament is considered plausible for both literal and allegorical interpretation, and more study of additional passages is needed.
[1] New King James Version, 1982, Thomas Nelson, Inc.