2 Thessalonians 2:7

for the secret of the lawlessness doth already work, only he who is keeping down now will hinder -- till he may be out of the way,

Revelation 17:5

and upon her forehead was a name written: 'Secret, Babylon the Great, the Mother of the Whores, and the Abominations of the earth.'

Revelation 17:7

and the messenger said to me, 'Wherefore didst thou wonder? I -- I will tell thee the secret of the woman and of the beast that is carrying her, which hath the seven heads and the ten horns.

1 John 2:18

Little youths, it is the last hour; and even as ye heard that the antichrist doth come, even now antichrists have become many -- whence we know that it is the last hour;

1 John 4:3

and every spirit that doth not confess Jesus Christ in the flesh having come, of God it is not; and this is that of the antichrist, which ye heard that it doth come, and now in the world it is already.

Acts 20:29

for I have known this, that there shall enter in, after my departing, grievous wolves unto you, not sparing the flock,

Colossians 2:18-23

let no one beguile you of your prize, delighting in humble-mindedness and in worship of the messengers, intruding into the things he hath not seen, being vainly puffed up by the mind of his flesh,

1 Timothy 3:16

and, confessedly, great is the secret of piety -- God was manifested in flesh, declared righteous in spirit, seen by messengers, preached among nations, believed on in the world, taken up in glory!

2 Timothy 2:17-18

and their word as a gangrene will have pasture, of whom is 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, confessedly, great is the secret of piety -- God was manifested in flesh, declared righteous in spirit, seen by messengers, preached among nations, believed on in the world, taken up in glory!
Revelation 17:5
and upon her forehead was a name written: 'Secret, Babylon the Great, the Mother of the Whores, and the Abominations of the earth.'

Doth

Acts 20:29
for I have known this, that there shall enter in, after my departing, grievous wolves unto you, not sparing the flock,
Colossians 2:18
let no one beguile you of your prize, delighting in humble-mindedness and in worship of the messengers, intruding into the things he hath not seen, being vainly puffed up by the mind of his flesh,
2 Timothy 2:17
and their word as a gangrene will have pasture, of whom is Hymenaeus and Philetus,
1 John 2:18
Little youths, it is the last hour; and even as ye heard that the antichrist doth come, even now antichrists have become many -- whence we know that it is the last hour;
1 John 4:3
and every spirit that doth not confess Jesus Christ in the flesh having come, of God it is not; and this is that of the antichrist, which ye heard that it doth come, and now in the world it is already.

He who

2 Thessalonians 2:6
and now, what is keeping down ye have known, for his being revealed in his own time,