What is the Second Coming of Christ?

Short answer

The Second Coming is the promise that Jesus Christ will return to earth visibly and in glory, as He went up to heaven. He will raise the dead in Christ, gather His people and judge the world, and no one knows the day.

The Second Coming is the Christian hope that Jesus Christ, who died, rose again and went up to heaven, will return. The Bible speaks of it again and again, and for the first Christians it was a source of comfort and a reason to live faithfully. Christians agree that He will come; they differ about some details of when and how, and those differences are worth stating honestly.

He will return

When Jesus ascended, His disciples stood looking up into the sky. Two angels spoke to them.

Which also said, Ye men of Galilee, why stand ye gazing up into heaven? this same Jesus, which is taken up from you into heaven, shall so come in like manner as ye have seen him go into heaven.
Acts 1:11 · King James Version (1769)

The angels’ words are both a promise and a gentle push: the disciples have work to do on earth. John MacArthur says that Christ will return to earth the same way He ascended, in a cloud, and will restore His kingdom. William MacDonald calls this verse a clear promise of the Lord’s return to establish His kingdom on earth, and distinguishes it from the gathering of the church to Him.

Matthew Henry draws a practical lesson. The disciples were eager to know what their Master had not told them, and Henry warns against a desire for forbidden knowledge. When we stand gazing and idle, he writes, the thought of the second coming should wake us up; when we stand trembling, it should comfort us.

How He will come

Jesus Himself described the day in His talk on the Mount of Olives.

And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory.
Matt 24:30 · King James Version (1769)

What is the sign of the Son of Man? MacArthur and the New Geneva Study Bible both read it as Christ Himself, or the first moments of His coming. MacDonald notes that we are not told what the sign will be and that some also take it to be the Son of Man Himself. MacArthur says the mourning of the tribes of the earth is sorrow over their rebellion against God, and that Israel in particular will grieve over having rejected the Messiah.

Not every reader takes the passage the same way. The New Geneva Study Bible mentions that some think these verses describe the fall of Jerusalem and the spread of the gospel, but argues that the language of verse 31 matches other passages about the Second Coming and judgment. Matthew Henry sees in the whole discourse a prophecy of the destruction of Jerusalem that was also a picture of the later coming of Christ at the end of time.

What it means for believers

Paul wrote about the Lord’s return to comfort Christians who were grieving over those who had died.

For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first: Then we which are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air: and so shall we ever be with the Lord.
1 Thess 4:16–17 · King James Version (1769)

Matthew Henry says that the teaching of the resurrection and of Christ’s coming is a remedy for the fear of death and excessive sorrow: those who died in Jesus are not lost. The New Geneva Study Bible says that the passage was given to comfort the grieving, and that its main point is that all the righteous will be with the Lord and with one another. It adds that the text does not give an exact order of the last events, for example whether those gathered in the clouds go to earth or to heaven.

Here Christians do differ. John MacArthur understands the “catching up” of living believers as the Rapture, which he places before the time of tribulation and distinguishes from Christ’s coming in judgment. William MacDonald also describes it as the first stage of the Lord’s return, and in Acts 1:11 he sees not the Rapture but the reign. Other Christians understand the gathering of believers and Christ’s visible coming in glory as one event. The simplest reading of the passage is that Jesus Himself will come down, believers who have died will rise, and all who are His will be with Him forever.

When will it happen?

Jesus gave an answer that frustrates all calculations: no one knows the day or the hour (Matthew 24:36). The New Geneva Study Bible says this saying puts an end to attempts to predict when Christ will return. MacDonald reads it as a warning not to be tempted to set dates or to believe those who do. MacArthur adds that Christ stresses faithfulness, watchfulness and readiness instead.

So the Second Coming is not a puzzle to solve but a promise that shapes the way we live: with hope when we are weary, with patience when evil seems to win, and with readiness. It is also part of the good news of Jesus, who came once to save and will come again to complete what He began. See also What are the signs of the end times? and Bible verses about hope.