Malachi 4:5-6 seems to be talking about the coming of Elijah in -spirit- in two dispensations. The first is fulfilled by John the Baptist. Who fulfills the second?

Elijah is called Elias in the New Testament, depending upon the translation. Matthew 17:10-13 (NASV) says, “And His disciples asked Him, saying, “why then do the scribes say that Elijah must come first?  And He answered and said, Elijah is coming and will restore all things; but I say to you, that Elijah already came, and they did not recognize him, but did to him whatever they wished.  So also the Son of Man is going to suffer at their hands.  Then the disciples understood that he had spoken to them about John the Baptist.”  John the Baptist tried to prepare as many hearts as possible to accept Jesus, but most of the Jews were not ready to receive either Jesus or John’s words. 

Additionally, there is a second, greater fulfillment. Just as John the Baptist, in the spirit of Elijah, introduced and made ready the way of Jesus at His first advent, at Jesus’ second coming, a greater than John—a company of believers whom he represented—will prepare the way for the reception of the glorious and complete Christ.

The second, greater fulfillment refers to the Church in the flesh. The Christ in the flesh, Head and body, is the Elijah or forerunner of the Church in glory, Jehovah’s Anointed. Their mission is to reprove error and sin, and to point to the coming Kingdom of glory. Our Lord Jesus and the apostles, and all the faithful in Christ Jesus since, are of this great antitypical Elijah, prophet or teacher.

Just as John the Baptist failed to reform Israel, so the Church in the flesh will fail to reform the world before the glorious kingdom of Christ. 2 Timothy 3:1-13 refers directly to the perilous times of the last days of this age. He points out its high-minded, pleasure-loving and good-despising characteristics. No, the world will not be Christian at our Lord’s return. It will be during Christ’s reign that nations shall beat their swords into ploughs…and (Isaiah 2:2-4).Then “no longer will a man teach his neighbor, or a man his brother, saying, ‘Know the LORD,’ because they will all know me from the least of them to the greatest,…I will put my law in their minds and write it on their hearts. I will be their God, and they will be my people.” Jeremiah 31:34, 33.