It is important to differentiate between the words immediate and imminent. Immediate speaks of taking effect without delay, which does not allow for any intervening events. But imminent speaks of impendingthat is, it may happen at any time. Some other events can intervene, but this does not affect the fact of the return. In the New Testament, the coming of Christ is set forth as imminent rather than immediate.1This tension between certainty and uncertainty leads to several important observations:
A. T. Pierson stated, 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. . . . Since we never know exactly when an imminent event will occur, three things are true. First, we cannot count on a certain amount of time transpiring before the imminent event happens; therefore, we should always be prepared for it to happen at any moment. Second, we cannot legitimately set a date for its happening. As soon as we set a date for an imminent event, we destroy the concept of imminency because we thereby say that a certain amount of time must transpire before that event can happen. A specific date for an event is contrary to the concept that the event could happen at any moment. Third, we cannot legitimately say that an imminent event will happen soon. . . . an imminent event may take place within a short time, but it does not have to do so in order to be imminent. Thus imminent is not equal to soon.2Events which are seen as imminent can never be said to follow upon some other non-imminent event, for that would establish a precursor to the imminent event thereby destroying its imminency. This is a key factor in favor of the pretribulational rapture of the Church. For if the Church remains to witness the signing of the 7-year covenant by Antichrist (Dan. Dan. 9:27) or the abomination of desolation (Dan. Dan. 12:11; Mtt. Mat. 24:15) as pre-wrath and post-tribulational rapture positions teach, then the coming of Jesus for His church (1Th. 1Th. 4:17) is no longer imminent and the Church will begin to watch for Antichrist rather than Christ!
No other prophecy in the Bible remains to be fulfilled before the imminent event occurs. Therefore, if two prophesied events are imminent [the rapture and the beginning of the Day of the Lord], neither can precede the other... If both the rapture of the church and the beginning of the day of the Lord are occurrences that could come at any moment, the timing of the rapture is not open for debate. The only way that both events could be imminent is for them to be simultaneous. If one preceded the other even by a brief moment, the other would not be imminent because of the sign provided by the earlier happening. This fact constitutes strong biblical support for the pretribulational rapture.3
The doctrine of imminence forbids the participation of the church in any part of the seventieth week. The multitude of signs given to Israel to stir them to expectancy would then also be for the church, and the church could not be looking for Christ until these signs had been fulfilled. The fact that no signs are given to the church, but she, rather, is commanded to watch for Christ, precludes her participation in the seventieth week.4The writers of Scripture anticipated that many would scoff at the delay in promise of His soon coming: Mat. 24:36, Mat. 24:39; 2Pe. 2Pe. 3:3, 2Pe. 3:4).5
3 Robert L. Thomas, Imminence in the NT, Especially Pauls Thessalonian Epistles, in Richard L. Mayhue, ed., The Masters Seminary Journal, vol. 13 no. 1 (Sun Valley, CA: The Masters Seminary, Spring 2002), 191,213.