The Bible speaks a lot about how the Day of the Lord or the return of the Lord will come as a thief in the night. For many that day will be Imminent:
- 2 Pet 3:10 - But the day of the Lord will come like a thief, in which the heavens will pass away with a roar and the elements will be destroyed with intense heat, and the earth and its works will be burned up.
- Rev 3:3 - So remember what you have received and heard; and keep it, and repent. Therefore if you do not wake up, I will come like a thief, and you will not know at what hour I will come to you.
- 1 Thes 5:1-2 - Now as to the times and the epochs, brethren, you have no need of anything to be written to you. For you yourselves know full well that the day of the Lord will come just like a thief in the night.
- and many others
However, almost all of these passages also speak of a readiness of the believer. It will catch the unbeliever off guard, but the Church should be watching:
- Rev 3:3 - Therefore if you do not wake up
- 1 Thes 5 - when they are saying peace and safety, then sudden destruction. The Church will be aware of this and not caught off guard.
- 2 Pet 3 - looking for and hastening the coming of the day of God. We are paying attention to it getting closer.
- Luke 21:36 - watch and pray you may be counted worthy to escape.
We can also see that there are two events that precede the rapture. 2 Thes 2:1-3 says that there will first be a falling away, and then the man of lawlessness will be revealed. This will happen before we are gathered to Christ. I believe that the church will be raptured before the wrath of God comes in Rev 6:17, and the true Church will know the coming of the Lord is soon. We may not know the exact day, but it will not catch us off guard. I believe we will see the Antichrist revealed. Revealed could mean he is born, he is rising in power, or he makes a covenant with Israel, but I think the church will know who he is before Jesus takes us home.