The first Christians had no Bible but the Old Testament, and perhaps the use of some of the non-canonical texts like the Book of Enoch. Mostly they relied on the wisdom and teaching of the church Fathers, who had the exact same Bible. It's more prudent of us to search for the truths and prophecies of end-times things in the Old Testament, because the New Testament was written with knowledge coming from the Old Testament (through revelation, I presume).
Having been a scoffer of pre-tribulation rapture ideas for quite some time, I've had to bite the bullet a bit and take a look at prophetic types in the ancient texts, because it seems there is some hint at a God-lover exit before the final ka-boom takes place. Jesus said the end will be like the days of Noah and like the days of sodom and Gomorrah (which can refer to more than one aspect), so let's take a look at what these might be "saying" to us in the here/now.
Lots of people think the genetic free-for-all leading up to the ark was the cause for the flood, and it makes a lot of sense when you consider the effect that angels producing offspring with human women could have - an almost irretrievably fallen "race" (literally, in this sense) if it was allowed to continue. It got so bad, and so widespread (the Book of Enoch says there were 180 some odd thousand of these hybrids wreaking havoc on the earth), that God found only Noah to be "perfect" in his generation.
There is much to be said here about genetic toggles in our day, and about the "beast" (which is flesh without spirit) being some sort of human clone who can be indwelled by Lucifer without any opposition by the flesh's owner (being absent). However, Noah prophesies a rapture for the beloved, and those who've chosen Him. Noah and his family were taken into the ark to "escape" (Gen 7:7) the wrath of the flood, were taken up by the waters and sat overtop the soak until it had accomplished all it was sent for. Then they came back down with the receding water, and exited the ark. Noah and his family would, of course, represent the chosen of God (I have to dread the day of "disappearing" if it comes and many who think they're in are in fact "left behind"; I've done a lot of writing in this blog about what it means to be saved, and perhaps what Jesus meant when he said "many are called, but few are chosen", or "narrow is the path... and only a few find it"; I suspect the "rapture" will be the most devastating day in history). It seems this is some sort of prophetic type, which can not be confirmed if it wasn't part of a couple (or some assortment of similar types).
Sodom & Gomorrah
Later in Genesis, we come to a 1-year span absolutely jam-packed with events, starting with a vist by God to Abraham. Here's a quick summary: God visits and tells Abraham, "I will surely return to you about this time next year, and Sarah your wife will have a son" (18:10). Sarah laughs (an unbelieving end-times Israel?). God tells Abraham what he's down for, which is to check out S&G, to see if it really deserves punishment, as He has heard. Abraham pleads for S&G. God's two companions arrive at Sodom (seems God went home), and meet Abraham's cousin Lot, who insists they stay with him (knowing the brutality of the town's inhabitants). The townsmen come for them and demand to have sex with the visitors (perhaps they knew angels were in town and wanted to become "men of renown" like the days of Noah when angels slept with humans?). The two angels (perhaps a prophecy of the Two Witnesses in Rev 11) then make their decision and tell Lot and all his family to immediately leave the city to escape the judgment, and they did. And with the rising of the sun (another prophetic type, in 19:23), the burning sulfur began to rain down on the cities and they were completely and utterly destroyed. Later, Lot's 2 daughters sleep with him while he is sleeping (not sure what this could typify), Abraham has another encounter with a King where he pretends his wife is his sister (which happened before), and finally Isaac is born (perhaps a prophecy of the coming of Christ).
There's so much in there, but my main point is on the prophetic parallel to an escape from judgment by the faithful - in the end, a rapture. There has been no contest, really, that there will be one, it's just a matter of when. And by reading Revelation, we can certainly see that the final judgment will only be the culmination of a series of horrible events. The question, then, is if the escape is from the final event or from the series of events?
Interesting to note also that the very bizarre occurences of Genesis in particular, and the bizarre moral choices of the "elect" and "righteous" begin to make some sense when we consider the stories a prophetic type (Example: Lot offered his 2 virgin daughters to the townsmen in place of the 2 strangers who had come to visit. What the...?).
When you take this approach to Genesis, and even the rest of the Pentateuch, you'll actually see the repition of it all, which could lead to further confirmation. An excellent example of this is found in Judges 19-20, which is a heart-breaking, stomach-churning account of a Levite and his concubine. They enter a town as visistor/travellers, and the townsmen surround the house like they did in Sodom, and said: "Bring out the man who came to your house so we can have sex with him" (Jd 19:22). This leads to a civil war between Israel and the tribe of Benjamin, where they are almost completely wiped out. This is not a story told, but I'd strongly encourage you to read it. It comes shortly after the death of Samson, whose story can prophetically speak of the the time and ministry of the Two Witnesses again (IMO).
Very interesting, this Bible of ours.