2 Thessalonians 2:7

For the mystery of lawlessness [rebellion against divine authority and the coming reign of lawlessness] is already at work; [but it is restrained] only until he who now restrains it is taken out of the way.

Revelation 17:5

And on her forehead a name was written, a mystery: “BABYLON THE GREAT, THE MOTHER OF PROSTITUTES (false religions, heresies) AND OF THE ABOMINATIONS OF THE EARTH.”

Revelation 17:7

But the angel said to me, “Why do you wonder? I will explain to you the mystery of the woman and of the beast that carries her, which has the seven heads and ten horns.

1 John 2:18

Children, it is the last hour [the end of this age]; and just as you heard that the antichrist is coming [the one who will oppose Christ and attempt to replace Him], even now many antichrists (false teachers) have appeared, which confirms our belief that it is the last hour.

1 John 4:3

and every spirit that does not confess Jesus [acknowledging that He has come in the flesh, but would deny any of the Son’s true nature] is not of God; this is the spirit of the antichrist, which you have heard is coming, and is now already in the world.

Acts 20:29

I know that after I am gone, [false teachers like] ferocious wolves will come in among you, not sparing the flock;

Colossians 2:18-23

Let no one defraud you of your prize [your freedom in Christ and your salvation] by insisting on mock humility and the worship of angels, going into detail about visions [he claims] he has seen [to justify his authority], puffed up [in conceit] by his unspiritual mind,

1 Timothy 3:16

And great, we confess, is the mystery [the hidden truth] of godliness:He (Jesus Christ) who was revealed in human flesh,
Was justified and vindicated in the Spirit,
Seen by angels,
Preached among the nations,
Believed on in the world,
Taken up in glory.

2 Timothy 2:17-18

and their teaching will spread like gangrene. So it is with Hymenaeus and Philetus,

Treasury of Scripture Knowledge

Summary

For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.

Bible References

The mystery

1 Timothy 3:16
And great, we confess, is the mystery [the hidden truth] of godliness:He (Jesus Christ) who was revealed in human flesh,
Was justified and vindicated in the Spirit,
Seen by angels,
Preached among the nations,
Believed on in the world,
Taken up in glory.
Revelation 17:5
And on her forehead a name was written, a mystery: “BABYLON THE GREAT, THE MOTHER OF PROSTITUTES (false religions, heresies) AND OF THE ABOMINATIONS OF THE EARTH.”

Doth

Acts 20:29
I know that after I am gone, [false teachers like] ferocious wolves will come in among you, not sparing the flock;
Colossians 2:18
Let no one defraud you of your prize [your freedom in Christ and your salvation] by insisting on mock humility and the worship of angels, going into detail about visions [he claims] he has seen [to justify his authority], puffed up [in conceit] by his unspiritual mind,
2 Timothy 2:17
and their teaching will spread like gangrene. So it is with Hymenaeus and Philetus,
1 John 2:18
Children, it is the last hour [the end of this age]; and just as you heard that the antichrist is coming [the one who will oppose Christ and attempt to replace Him], even now many antichrists (false teachers) have appeared, which confirms our belief that it is the last hour.
1 John 4:3
and every spirit that does not confess Jesus [acknowledging that He has come in the flesh, but would deny any of the Son’s true nature] is not of God; this is the spirit of the antichrist, which you have heard is coming, and is now already in the world.

He who

2 Thessalonians 2:6
And you know what restrains him now [from being revealed]; it is so that he will be revealed at his own [appointed] time.