I believe the Bible teaches the tribulation will begin after the rapture of the church. And when does the rapture occur? The Bible teaches it is imminent—it could occur at any moment.
In Revelation 6, when John begins to describe the tribulation period, there is absolutely no reference to the church on earth. Revelation 4–5 indicates that the church age will end prior to the tribulation and Christians will be worshiping the Lord in heaven. The elders, representing the church, are singing praise to the Lamb who has delivered them from God’s wrath (see Revelation 3:10).
This is an important point to make because as long as the church is still on the earth, the tribulation is still in the future. The tribulation will not begin until after the rapture of the church.
There are those who believe the tribulation has already occurred and we are living in the millennial period. This requires biblical prophecy to be spiritualized. A literal interpretation of passages describing the tribulation reveals nothing in history that comes close to matching the events described in Matthew 24 or in Revelation 6 and onward.
Just to illustrate, Daniel 9 clearly reveals that the Antichrist will desecrate the temple, thus indicating that the temple has to be rebuilt. I visited Israel recently, and I can attest to the fact that there is no temple there!
There are other prophecies as well, and I deal with them in detail in my teaching series through Revelation. But the key truth regarding the timing of the tribulation is that it has not yet begun but Jesus promises that He will come “soon.” Therefore, we are to live with the expectation the Lord could come at any moment for His church, thus ushering in the beginning stages of the tribulation events.