Man of Sin
The man of sin (Greek: ὁ ἄνθρωπος τῆς ἁμαρτίας, ho anthrōpos tēs hamartias) or man of lawlessness (ἀνομίας, anomias), man of rebellion, man of insurrection, or man of apostasy is a figure referred to in the Christian Bible in the Second Epistle to the Thessalonians. He is usually equated with the Antichrist in Christian eschatology.
Son of Perdition
The son of perdition (Biblical Greek: ὁ υἱός τῆς ἀπωλείας, ho huios tēs apōleias) is a phrase associated with a demoniacal title that appears in the New Testament in the Gospel of John 17:12 and in the Second Epistle to the Thessalonians 2:3.
In John 17:12, Jesus, in reference to Judas Iscariot, says that of all his disciples, none has been lost except the "son of perdition":
While I was with them in the world, I kept them in thy name: those that thou gavest me I have kept, and none of them is lost, but the son of perdition; that the scripture might be fulfilled.
— John 17:12, King James Version, 1611
In 2 Thessalonians 2:3, Paul referred to "the son of perdition":
Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition.
— 2 Thessalonians 2:3, King James Version, 1611
He appears to equate this image with the Man of Sin.
Some theologians and scholars also consider "the beast that goes into perdition" mentioned in Revelation 17:8 and 17:11 to be references to the son of perdition.[11][12]
Katechon
The katechon (from Greek: τὸ κατέχον, "that which withholds", or ὁ κατέχων, "the one who withholds"), also known as the restrainer, is a biblical term referring to something that must be removed before the arrival of the "man of sin." Mentioned in the New Testament, the katechon's uncertain identity has been debated amongst Christian scholars. Common interpretations for the identity include the government, the church, and the Holy Spirit.