I think that you should locate every mention of the term "Church" in Revelation.
And then ask yourself who is it that is doing the preaching during the time of the tribulation period.
Bearing in mind of course that the 144,000 are of the sons of Jacob.
You will find that the term Church is never mentioned during the time of the tribulation.
You'll also find that only Israelites are witnessing to the world during the time of the tribulation.
Luke 21:20-28 below clearly shows the (Church) present on earth during the tribulation, right up to the second coming of Jesus Christ in the heavens.
Verse 24 states (They Shall Fall) speaking to the Church present, about the Jews in Jerusalem during the fulfilling of the gentiles, also seen in Revelation 11:2
Luke 21:20-28KJV
20 And when ye shall see Jerusalem compassed with armies, then know that the desolation thereof is nigh.
21 Then let them which are in Judaea flee to the mountains; and let them which are in the midst of it depart out; and let not them that are in the countries enter thereinto.
22 For these be the days of vengeance, that all things which are written may be fulfilled.
23 But woe unto them that are with child, and to them that give suck, in those days! for there shall be great distress in the land, and wrath upon this people.
24 And
they shall fall by the edge of the sword, and shall be led away captive into all nations: and Jerusalem shall be trodden down of the Gentiles, until the times of the Gentiles be fulfilled.
25 And there shall be signs in the sun, and in the moon, and in the stars; and upon the earth distress of nations, with perplexity; the sea and the waves roaring;
26 Men's hearts failing them for fear, and for looking after those things which are coming on the earth: for the powers of heaven shall be shaken.
27 And then shall they see the Son of man coming in a cloud with power and great glory.
28 And when these things begin to come to pass, then look up, and lift up your heads; for your redemption draweth nigh.