Commenting on the belief that Elijah (NT: Elias) will return before the parousia, Catholic theologian Joseph Pohle wrote:
So far as it regards Elias, this belief is based on the prophecy of Malachias: “Behold I will send you Elias 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 strike the earth with anathema.” “Elias the prophet” cannot be identical with John the Baptist, as some have thought, because the Septuagint expressly calls him “the Thesbite.” Moreover, our Lord Himself clearly distinguishes between the two, and ascribes to Elias precisely the role that was attributed to him by His contemporaries. Matt. 17:11 sq.: “But he answering, said to them: Elias indeed shall come, and restore all things; but I say to you that Elias is already come . . . Then the disciples understood that he had spoken to them of John the Baptist.” St. Augustine explains this text as follows: “As there are two advents of the Judge, so there are two precursors . . . He sent before Him the first precursor and called him Elias, because Elias was to take the same part in the second coming that John had in the first.”
From what we have said it further appears that the phrase “dies Domini” does not mean the first coming of Christ as the Messias, but His second coming as the Universal Judge. The day of His Incarnation was a day of mercy and blessing; the day of the Last Judgment will be a “day of terror.” (Joseph Pohle, Eschatology or The Catholic Doctrine of the Last Things: A Dogmatic Treatise [St. Louis: B. Herder Book Co., 1920; repr., Veritatis Splendor Publications, 2014], 103-4)
