OK, let's see what was said by the very earliest Christian writer who said about the rapture.
Those nations however, who did not of themselves raise up their eyes unto heaven, nor returned thanks to their Maker, nor wished to behold the light of truth, but who were like blind mice concealed in the depths of ignorance, the word justly reckons as waste water from a sink, and as the turning-weight of a balancein fact, as nothing; so far useful and serviceable to the just, as stubble conduces towards the growth of the wheat, and its straw, by means of combustion, serves for working gold. And therefore, when in the end the Church shall be suddenly caught up from this, it is said, There shall be tribulation such as has not been since the beginning, neither shall be. For this is the last contest of the righteous, in which, when they overcome they are crowned with incorruption. (Against Heresies, by Irenaeus, book V, chapter XXIX, section 1) This is thought to have been written between the years 186 and 188.
We need to notice the following elements in this short statement:
First, the church will be "suddenly caught up."
Second, after the church is "Suddenly caught up," "There shall be tribulation such as has not been since the beginning, neither shall be." Lest anyone claim that this is not specifically stated to be after the church is "suddenly caught up," please note that the grammatical construction (when) -- (one event takes place) -- (a second event takes place) has two possible meanings. It either means that the two events will take place at the same time or it means that the second event will take place after the first event. But it cannot mean that the second event takes place before the first event. In this case the first event is clearly instantaneous and the second event will obviously consume a significant period of time. So it is unreasonable to argue that the writers intention was anything other than to state that this tribulation would take place after the church is suddenly caught up.
Third, this period of tribulation is specifically called "the last contest of the righteous." and it explicitly says of these righteous in this particular contest, "in which, when they overcome they are crowned with incorruption."
So this statement clearly teaches that the rapture will occur before the great tribulation.
One of the doctrines of dispensationalism is that, after the church is "suddenly caught up," there will be a righteous remnant that will undergo a great trial of faith, and that, when they triumph in this trial, they will be crowned with righteousness. Many dispensationalists differentiate between the tribulation (the entire seven year period) and the great tribulation (the last three and half years.) This appears to be the position held by Irenaeus.
There is also other evidence of similar doctrine having been taught in ancient times. Among these we find the following statement by John of Crysostem which is thought to have been written sometime between the years 395 and 407.
2 Thessalonians ii. 69
And now ye know that which restraineth, to the end that he may be revealed in his own season. For the mystery of lawlessness doth already work: only there is one that restraineth now, until he be taken out of the way. And then shall be revealed the lawless one, whom the Lord Jesus shall slay with the breath of His mouth, and bring to nought by the manifestation of His coming: even he whose coming is according to the working of Satan.
One may naturally enquire, what is that which withholdeth, and after that would know, why Paul expresses it so obscurely. What then is it that withholdeth, that is, hindereth him from being revealed? Some indeed say, the grace of the Spirit, but others the Roman empire, to whom I most of all accede. Wherefore? Because if he meant to say the Spirit, he would not have spoken obscurely, but plainly, that even now the grace of the Spirit, that is the gifts, withhold him. (Homilies on 2 Thessalonians, Homily IV, by John Chrysostom, Volume XIII of Nicene and Post Nicene Fathers, series 2, as translated by James Tweed and edited by Philip Schaff, as found in the American edition edited by Phillip Schaff , and as found online at [link removed]
Although it is strangely stated, this appears to be a saying that some in the day of John of Crysostom were saying that the restrainer of 2 Thessalonians 2:6 is the Holy Spirit. As this is one of the key elements of the doctrine of the pre-tribulation rapture, this appears to be evidence that some were teaching this doctrine around the beginning of the fifth century. This is all the more important historically, because the man who mentioned it did not himself believe this doctrine.
So there is indeed evidence that the very earliest written Christian doctrine on the timing of the rapture put it before, not after, the great tribulation, and other exceedingly ancient writings suggest that the doctrine was still being taught in the fourth century, during the time of John of Crysostom. (C 347-407)
Although it is strangely stated, this appears to be a saying that some in the day of John of Crysostom were saying that the restrainer of 2 Thessalonians 2:6 is the Holy Spirit. As this is one of the key elements of the doctrine of the pre-tribulation rapture, this appears to be evidence that some were teaching this doctrine around the beginning of the fifth century. This is all the more important historically, because the man who mentioned it did not himself believe this doctrine.
But in addition to these critically important very early comments, we have absolute proof that the claim that the church had always taught the doctrine of the post tribulation rapture before a few hundred years ago is completely incorrect. This proof is found in a document, whose age and author is unknown, but which is known to have been in Church libraries before the year 800. Based on events referred to in this document as impending, various scholars have estimated its date from as early as 373 to as late as 627. As scholars do not believe the unknown author could have been the famous Ephraem the Syrian, (who is also known as Ephraem of Nisbis) they call this unknown author Pseudo-Ephraem. This document says,
Why therefore do we not reject every care of earthly actions and prepare ourselves for the meeting of the Lord Christ, so that he may draw us from the confusion, which overwhelms all the world? Believe you me, dearest brother, because the coming (advent) of the Lord is nigh, believe you me, because the end of the world is at hand, believe me, because it is the very last time. Or do you not believe unless you see with your eyes? See to it that this sentence be not fulfilled among you of the prophet who declares: Woe to those who desire to see the day of the Lord! For all the saints and elect of God are gathered, prior to the tribulation that is to come, and are taken to the Lord lest they see the confusion that is to overwhelm the world because of our sins. (On the Last Times, the Antichrist, and the End of the World, author unknown but called Pseudo-Ephraem, section 2.)
These three truly ancient statements are evidence that the post tribulation rapture was not the original doctrine of the church, and are conclusive proof that the claim that the church had always taught the post tribulation rapture until a few hundred years ago is completely incorrect.