First, God's end times plans are his and that doesn't depend on us believing anything. Those poor folk who are not spiritually "born again" at the Rapture are, by definition, not the Bride of Christ and nothing else matters. There is nothing in scripture to support the odd idea that "some born again folk will go this way and some will go that way" at the pre-trib Rapture, depending on what they believe.
Bottom line, Jesus says his followers will be raised in perfection but non-believers clearly will not and, from that, we can deduce that no believers will ever be left behind. (Matt 7:27 and on) ???
Who will be the primary world wide evangelical witness team during the Tribulation? God's 144,000 selected, protected and empowered Jews! (Rev 7:1-10)