We believe that our Lord and Savior Jesus Christ could come in the clouds at any-moment and take His church to be with Him to His Father's house (John 14:1-3). What a great hope, that while you are reading this article, our Lord could return and rapture His church. We have come to call this any-moment hope of the rapture an imminent event.
The English word "imminent" (of Latin derivation) can be used in many ways, it is used to note the New Testament teaching that Christ could return and rapture His church at any-moment, without prior signs or warning. Use of the term "imminency" entered the lexicon of American Evangelicalism around the end of the last century in contrast to the dominate, but waning, postmillennialism which taught that Christ's coming was not imminent. Postmillennialism held that Christ's return must first await the Christianization of the world by the Church. By the 1930s, it was common to pack into one theological expression - imminency - all of the many New Testament ways in which Christ's coming for His Church is said to be possible at any-moment. Thus, imminency and the any-moment return of Christ became synonyms for the pretribulational rapture of the church.
In fact, imminency is such a powerful argument for pretribulationism that it is one of the most frequent and fiercely attacked doctrines by our opponents. Non-pretribulationists sense that if the New Testament teaches imminency, then pretribulationism is virtually assured.
Definition of Imminency
What is the biblical definition of imminency? Four important elements contribute to a pretribulational understanding of imminency. First, imminency means that the rapture could take place at any moment. While other events may take place before the rapture, no event must precede it. If prior events are required before the rapture, then the rapture could not be described as imminent. Thus, if any event were required to occur before the rapture, then the concept of imminency would be destroyed.
Second, since the rapture is imminent and could happen at any moment, then it follows that one must be prepared for it to occur at any time, without sign or warning.
Third, imminency eliminates any attempt at date setting. Date setting is impossible since the rapture is signless (i.e., providing no basis for date setting) and if imminency is really true, the moment a date was fixed then Christ could not come at any moment, destroying imminency. Fourth, Renald Showers says, "A person cannot legitimately say that an imminent event will happen soon. The term 'soon' implies that an event must take place 'within a short time (after a particular point of time specified or implied).' By contrast, an imminent event may take place within a short time, but it does not have to do so in order to be imminent. As I hope you can see by now, "imminent" is not equal to 'soon.'"  A. T. Pierson has noted that, "Imminence is the combination of two conditions, viz.,: certainty and uncertainty. By an imminent event we mean one which is certain to occur at some time, uncertain at what time." 
Imminency in the New Testament
The fact that Christ could return, but may not soon, at any moment, yet without the necessity of signs preceding His return, requires the kind of imminence taught by pretribulationism.
What New Testament passages teach this truth? Those verses stating that Christ could return at any moment, without warning and those instructing believers to wait and look for the Lord's coming teach the doctrine of imminence. Note the following New Testament passages:
·1 Corinthians 1:7 - "awaiting eagerly the revelation of our Lord Jesus Christ,"
·1 Corinthians 16:22 - "Maranatha."
·Philippians 3:20 - "For our citizenship is in heaven, from which also we eagerly wait for a Savior, the Lord Jesus Christ;"
·Philippians 4:5 - "The Lord is near."
·1 Thessalonians 1:10 - "to wait for His Son from heaven,"
·1 Thessalonians 4:15-18 - "For this we say to you by the word of the Lord, that we who are alive, and remain until the coming of the Lord, shall not precede those who have fallen asleep. For the Lord Himself will descend from heaven with a shout, with the voice of the archangel, and with the trumpet of God; and the dead in Christ shall rise first. Then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air, and thus we shall always be with the Lord. Therefore comfort one another with these words."
·1 Thessalonians 5:6 - "so then let us not sleep as others do, but let us be alert and sober."
·1 Timothy 6:14 - "that you keep the commandment without stain or reproach until the appearing of our Lord Jesus Christ,"
·Titus 2:13 - "looking for the blessed hope and the appearing of the glory of our great God and Savior, Christ Jesus;"
·Hebrews 9:28 - "so Christ . . . shall appear a second time for salvation without reference to sin, to those who eagerly await Him."
·James 5:7-9 - "Be patient, therefore, brethren, until the coming of the Lord. . . . for the coming of the Lord is at hand. . . . behold, the Judge is standing right at the door."
·1 Peter 1:13 - "fix your hope completely on the grace to be brought to you at the revelation of Jesus Christ."
·Jude 21 - "waiting anxiously for the mercy of our Lord Jesus Christ to eternal life."
·Revelation 3:11; 22:7, 12, 20 - "'I am coming quickly!'"
·Revelation 22:17, 20 - "And the Spirit and the bride say, 'Come.' And let the one who hears say, 'Come.'" ..."He who testifies to these things says, 'Yes, I am coming quickly.' Amen. Come, Lord Jesus."
It is significant that all of the above passages relate to the rapture and speak of the Lord's coming as something that could occur at any-moment, that it is imminent. This is why believers are waiting for a person - Jesus Christ - not just an event or series of events such as those related to the tribulation leading up to Christ's second advent in which He returns to the earth and remains for His millennial reign.
Imminence and Pretribulationism
Contemplation of the above passages indicates that Christ may come at any moment so that the rapture is actually imminent. Only pretribulationism can give a full, literal meaning to such an any-moment event. Other rapture views must redefine imminence more loosely than the New Testament would allow. Dr. Walvoord declares, "The exhortation to look for 'the glorious appearing' of Christ to His own (Titus 2:13) loses its significance if the Tribulation must intervene first. Believers in that case should look for signs."  If the pretribulational view of imminence is not accepted, then it would make sense to look for signs related to events of the tribulation (i.e., the anti-Christ, the two witnesses, etc.) and not for Christ Himself. But the New Testament, as demonstrated above, uniformly instructs the church to look for the coming of Christ, while tribulation saints are told to look for signs.
The New Testament exhortation to be comforted by the Lord's coming (John 14:1; 1 Thess. 4:18) would no longer have meaning if believers first had to pass through any part of the tribulation. Instead, comfort would have to await passage through the events of the tribulation. No, the church has been given a "Blessed Hope," in part, because our Lord's return is truly imminent.
The early church had a special greeting for one another, as recorded in 1 Corinthians 16:22, which was "Maranatha!" Maranatha consists of three Aramaic words: "Mar" ("Lord"), "ana" ("our"), and "tha" ("come"), meaning "our Lord, come." As with other New Testament passages, Maranatha only makes sense if an any-moment or imminent coming is understood. Such an understanding supports the pretribulationism.
No wonder these ancient Christians coined such a unique greeting which reflects an eager expectation of the Blessed Hope as a very real presence in their everyday lives providing a motivation for godly living, evangelism, and worldwide evangelism. The life of the church today could only be improved if "Maranatha" were to return as a sincere greeting on the lips of an expectant people. Maranatha!