I am wondering if you can please help me understand what the Bible is saying about John the Baptist when it refers to him coming in the spirit of Elijah? In Luke 1:17, it says John the Baptist will come in the "spirit and power of Elijah." In Matthew 11:14 Jesus says John is "Elijah who was to come." Malachi 4:5 says that God will send "Elijah the prophet." And John 1:21 says that John said that he wasn't Elijah. I'm wondering what these scriptures are saying and what the correct understanding is regarding John being Elijah or coming in the spirit and power of Elijah?
John the Baptist and Elijah were very similar characters. There were things about John's dress that reminds you of Elijah. "And John himself was clothed in camel's hair, with a leather belt around his waist; and his food was locusts and wild honey" (Matthew 3:4). Elijah, too, was known for his leather belt (II Kings 1:8) and as a prophet, he likely wore a coarse-haired garment (Zechariah 13:4). In hiding from Jezebel, Elijah lived in the wilderness (I Kings 19:4), though his food wasn't locust while he was there. John spent most of his ministry in the wilderness as well.
However, it is the personalities that are strikingly similar. Both Elijah and John were direct men. They didn't soften their words.
"And so it was, at noon, that Elijah mocked them and said, "Cry aloud, for he is a god; either he is meditating, or he is busy, or he is on a journey, or perhaps he is sleeping and must be awakened"" (I Kings 18:27).
"But when he saw many of the Pharisees and Sadducees coming to his baptism, he said to them, "Brood of vipers! Who warned you to flee from the wrath to come?"" (Matthew 3:7).
Both were unafraid to renounce the rulers of their day. Elijah rebuked Ahab so often that Ahab referred to him as his enemy (I Kings 21:20). Ahab's wife vowed to kill Elijah (I Kings 19:2). John told Herod that his marriage was unlawful (Mark 6:19) and Herod's wife desired to kill John (Mark 6:20).
Both Elijah and John dealt with people who were not following God trying to turn the hearts of the people back to God.
Both men, even though successful, doubted themselves. Elijah gave up when Jezebel threatened to kill him after his triumph over the false prophets on Mount Carmel (I Kings 19:1-10). John began to doubt whether Jesus really was the Christ after he spent time in prison (Matthew 11:2-6; Luke 7:18-23).
This does not mean that John was Elijah resurrected. When asked if he was Elijah, John answered, "No" (John 1:21). When asked who he was, "He said: "I am 'The voice of one crying in the wilderness: "Make straight the way of the LORD,"' as the prophet Isaiah said'" (John 1:23). Malachi also mentioned this prophet. "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). An angel told Zacharias that John would fulfill that prophecy. "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" (Luke 1:17). Notice that the angel makes it clear. John and Elijah are not the same person. John would come with the same spirit and power that Elijah exhibited in his ministry. Jesus testified that John was the man whom Malachi spoke of. "And if you are willing to receive it, he is Elijah who is to come" (Matthew 11:14). Jesus didn't say John was Elijah, Jesus said that John was the Elijah who was predicted to come.