Before Christ’s return and the Day of the Lord, there will be an apostasy of the Christian Church:
2 Thessalonians 2:1-3 NKJV
Now, brethren, concerning the coming of our Lord Jesus Christ and our gathering together to Him, we ask you, not to be soon shaken in mind or troubled, either by spirit or by word or by letter, as if from us, as though the day of Christ had come. Let no one deceive you by any means; for that Day will not come unless the falling away comes first, and the man of sin is revealed, the son of perdition.
This appears to be happening right now. Christ also said His coming and the end of the world would happen when the world becomes like Sodom:
Luke 17:26-30 NKJV
And as it was in the days of Noah, so it will be also in the days of the Son of Man: They ate, they drank, they married wives, they were given in marriage, until the day that Noah entered the ark, and the flood came and destroyed them all. Likewise as it was also in the days of Lot: They ate, they drank, they bought, they sold, they planted, they built; but on the day that Lot went out of Sodom it rained fire and brimstone from heaven and destroyed them all. Even so will it be in the day when the Son of Man is revealed.