In 1844, there was the Great Disappointment when many people expected the 2nd advent to happen. I think we are heading for a second one in which millions of people who expect to be raptured away before seeing tribulation will experience a time of trouble like the world has never seen, lose faith and fall to the enemy.
We must prepare to persevere to the end and not expect peace and safety.
An unbiased reading of Matt. 24, 2 Peter 3, and 1&2 Thessalonians make it clear. The pretribulation rapture is not biblical.
2 Pet. 3:
4 And saying, Where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation.
9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.
10 But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up.