Signs that are to precede the general judgment
The Scriptures mention certain events which are to take place before the final judgment. These predictions were not intended to serve as indications of the exact time of the judgment, for that day and hour are known only to the Father, and will come when least expected. They were meant to foreshadow the last judgment and to keep the end of the world present to the minds of Christians, without, however, exciting useless curiosity and vain fears. Theologians usually enumerate the following nine events as signs of the last judgment:
General preaching of the Christian religion
Concerning this sign the Saviour says: “And this gospel of the kingdom, shall be preached in the whole world, for a testimony to all nations, and then shall the consummation come” (Matthew 24:14). This sign was understood by Chrysostom and Theophilus as referring to the destruction of Jerusalem, but, according to the majority of interpreters, Christ is here speaking of the end of the world.
Conversion of the Jews
According to the interpretation of the Fathers, the conversion of the Jews towards the end of the world is foretold by St. Paul in the Epistle to the Romans (11:25-26): “For I would not have you ignorant, brethren, of this mystery, . . . that blindness in part has happened in Israel, until the fullness of the Gentiles should come in. And so all Israel should be saved as it is written: There shall come out of Sion, he that shall deliver, and shall turn away ungodliness from Jacob”.
Return of Enoch and Elijah
The belief that these two men, who have never tasted death, are reserved for the last times to be precursors of the Second Advent was practically unanimous among the Fathers, which belief they base on several texts of Scripture. (Concerning Elijah see Malachi 4:5-6; Sirach 48:10; Matthew 17:11; concerning Enoch see Sirach 44:16)
**A great apostasy
As to this event St. Paul admonishes the Thessalonians (2 Thessalonians 2:3) that they must not be terrified, as if the day of the Lord were at hand, for there must first come a revolt (he apostasia).The Fathers and interpreters understand by this revolt a great reduction in the number of the faithful through the abandonment of the Christian religion by many nations. Some commentators cite as confirmatory of this belief the words of Christ: “But yet the Son of man, when he cometh, shall he find, think you, faith on earth?” (Luke 18:8). **
The reign of Antichrist
In the passage above mentioned (2 Thessalonians 2:3 sqq.) St. Paul indicates as another sign of the day of the Lord, the revelation of the man of sin, the son of perdition. “The man of sin” here described is generally identified with the Antichrist, who, says St. John (1 John 2:18), is to come in the last days. Although much obscurity and difference of opinion prevails on this subject, it is generally admitted from the foregoing and other texts that before the Second Coming there will arise a powerful adversary of Christ, who will seduce the nations by his wonders, and persecute the Church.
Extraordinary perturbations of nature
The Scriptures clearly indicate that the judgment will be preceded by unwonted and terrifying disturbances of the physical universe (Matthew 24:29; Luke 21:25-26). The wars, pestilences, famines, and earthquakes foretold in Matthew 24:6 sq. are also understood by some writers as among the calamities of the last times.
The universal conflagration
In the Apostolic writings we are told that the end of the world will be brought about through a general conflagration, which, however, will not annihilate the present creation, but will change its form and appearance (2 Peter 3:10-13; cf. 1 Thessalonians 5:2; Apocalypse 3:3, and 16:15). Natural science shows the possibility of such a catastrophe being produced in the ordinary course of events, but theologians generally tend to believe that its origin will be entirely miraculous.
The Trumpet of Resurrection
Several texts in the New Testament make mention of a voice or trumpet which will awaken the dead to resurrection (1 Corinthians 15:52; 1 Thessalonians 4:15; John 5:28). According to St. Thomas (Supplement 86:2) there is reference in these passages either to the voice or to the apparition of Christ, which will cause the resurrection of the dead.
"The sign of the Son of Man appearing in the heavens"
In Matthew 24:30, this is indicated as the sign immediately preceding the appearance of Christ to judge the world. By this sign the Fathers of the Church generally understand the appearance in the sky of the Cross on which the Saviour died or else of a wonderful cross of light.