Christians: Why does Paul say that we should let no man deceive us about the coming of Christ.....?

Gathering unto Him....that the day will not come until the Antichrist is revealed and there is a falling away of the church during tribulations? If the Antichrist is not revealed until half way into the Apocalypse, Christians must still be here. And if the dead are raised at the last trumpet, and we come to Christ after them, how can a rapture be before the first trumpet? And if Scripture calls this a gathering and then being caught-up after all is over, why the rapture deception?