The tribulation we as Christians currently experience comes from a fallen world under the governing of Satan. The Tribulation that is coming is a test on the whole world at the end of the age, that will come from Gods hand against sin.
Many seem to overlook that God is the source of judgment for the great tribulation on an unrepentant world.
Jesus promises assurance to the church of Revelation 3:10: Because you have kept the word of My perseverance, I also will keep you from the hour of testing, that hour which is about to come upon the whole world, to test those who dwell upon the earth. This testing will include all power and lying signs, wonders and miracles to deceive all who dwell on the earth.
That promise in Rev 3:10 can be accomplished in many ways. To assume it’s fulfilled by rapture is careless interpretation. It can be fulfilled by delay, and letting them die a natural death before it comes. 2 Thess clearly gives signs before Christ comes.