We do have a part, but only the part that involves acknowledgement of who Jesus is, then trust and acceptance. Clearly, true belief is more than just "believing". It is acceptance of the redemptive work of the Messiah to their own life. Then the HS places His seal on us that we are now Messiah's property. Anything other than that trust and acceptance is based in works. And Paul made it expressly clear that salvation is of faith, not works, lest anyone boast. Boasting is pride, which is sin.
And one might look at this whole idea of the pre-trip rapture being a fallacy in a slightly different ways.
For the post trib position, it would mean this.... "I will save you, you belong to me as my bride, but first I will beat the snot out of you and then we will go have dinner". So that one doesn't seem to fit Jesus' character very well. That flies in the face of "comfort one another with these words" (1 Thessalonians 4:17-18). And it also violates that no man knows the day or the hour.
A mid trib position (and even the Pre-Wrath version to some extent), though closer to realistic, fails to observe that no man knows the day or the hour. The period of the "Time of Jacob's Trouble" (Jeremiah 30:7), or Great Tribulation, starts when the false messiah establishes a covenant of protection with Israel. And then he breaks it at the mid point of 7 years and establishes himself in the temple as the true messiah (Daniel 9:27). Anyone at that time should know when that covenant begins, so would then know when the mid trib point is reached. That violates "no man knows the day or the hour" (Matthew 24:36 and Mark 13:32).
Amillennial, or denial of the literal millennium, is so far out in left field that it is almost tantamount to heresy, and quite probably is. It impugns the very character of God... that He doesn't mean what He says or says what He means. It is essentially saying that God was incompetent in what he laid out in hundreds of passages of the OT. One has to spiritualize or allegorize the scripture to extremes. When we get doing that, then no one can really ascertain the true meaning of scripture and it leads to all sorts of doctrinal problems. A close cousin of the Ammillennial position is Pretorism, that all of the prophecy of Revelation, Matthew, etc all was accomplished by 70 AD. Again, that is spiritualizing or allegorizing to extremes. But is comports well with that maxim in the computer science field... if you torture the data long enough, it will confess to anything.
That pretty much leaves a pre-trib position as one that aligns more with scripture and with the character of God. Even then, there is no way we can fully comprehend all that is going to happen. Isaiah 55:8-9 says explicitly that God's ways are higher than ours and His thoughts are higher than our thoughts. We get all arrogant in thinking we have all the truth and everything figured out.
Prophecy is pattern, as Paul was taught in the School of Gamaliel, still recognized as one of the most prominent teaching schools of rabbinic Judaism (Acts 22:3). and we can glean insight from God's previous patterns. And before you diss the idea of Gamaliel being just a rabbi, remember that what Jesus said in Matthew 22:37-40 was identical, almost a verbatim quote, to what Gamaliel told a student when asked to summarize the entire law while standing on one foot. Noah and his family entered the ark 7 days prior the rains starting. Lot had to be removed from Sodom before the angels could destroy the city and they told him that. And there are other patterns we can glean. So the idea that those who God calls righteous, those who have been bought and paid for by Jesus, will escape the wrath of God and the Great Tribulation is not as far fetched as some might suppose.
