John Chrysostom

But if there shall so much good arise out of the presence of Elias, why did He not send him at that time? We shall say, Because they then held Christ to be Elias, and yet believed not on Him. But they shall hereafter believe Elias, because when he shall come after so great expectation announcing Jesus, they will more readily receive what shall be taught by Him. But when He says that Elias is come already, He calls John the Baptist Elias from the resemblance of their ministry; for as Elias shall be the forerunner of His second coming, so was John the forerunner of His first. And He calls John Elias, to shew that His first coming was agreeable to the Old Testament, and to prophecy.