The title of your thread is that the rapture already occurred. Where?

Indeed, there has been great tribulation these past 20 centuries as recorded in Rev. 7: "And I said unto him, Sir, thou knowest. And he said to me, These are they which came out of great tribulation, and have washed their robes, and made them white in the blood of the Lamb" (v.14). This is not referring to the Great Tribulation at the end of this age in Matt. 24: "For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be" (v.21).

The generation in Matt. 24.34 is referring to this "wicked generation." Since this wicked generation continues to today, it must mean these things continue: "Verily I say unto you, This generation shall not pass, till all these things be fulfilled" (v.34). Particularly what has not occurred is verse 15: "When ye therefore shall see the abomination of desolation, spoken of by Daniel the prophet, stand in the holy place, whoso readeth, let him understand." Nor has verse 16: "Then let them which be in Judaea flee into the mountains." Nor has verse 22: "And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened." And on and on.

What are these "things that shall come to pass"? (Luke 21.36) They comprise the Tribulation at the end of this age commensurate with Daniel's final seven of 2,520 days (Dan. 9.27). God can't promise someone will escape the Tribulation unless through rapture because once in the Tribulation there will be many martyred Christians including those most spiritual Christians.

This has not happened yet. "For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming of the Son of man be. For wheresoever the carcase is, there will the eagles be gathered together. Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken: And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory. And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other" (Matt. 24.27-31).