The culmination of world events all seems to be leading in one direction. Christ himself outlined all these events and stated "these events will happen in a generation" prior to his return. Theologians commonly refer to the coming of Christ with the term parousia or (appearance). The Old Testament prophets foretold that the Messiah would appear to bring salvation and judgment. While the Old Testament messianic prophecies do not specifically distinguish between the two comings of Christ, the New Testament reveals Jesus to be the long-anticipated Messiah, who, in his first coming, died and rose again to secure the salvation of his people. The Old Testament spoke of the coming of Christ under the figure of the day of the Lord (yom YHWH), a day of salvation and judgment. The New Testament reveals that this "day" would be divided into two separate periods in which there would be two distinct appearances of Christ. According to Scripture, the second Advent could occur at any moment.
The writer of Hebrews described the return appearance of Christ when he stated, "Just as it is appointed for man to die once, and after that comes judgment, so Christ, having been offered once to bear the sins of many, will appear a second time, not to deal with sin but to save those who are eagerly waiting for him" (Hebrews 9:27-28).