For the mystery of lawlessness already works. Only there is one who restrains now, until he is taken out of the way.
Only he who now letteth - Who now hinders, or restrains - ὁ κατέχων ho katechōn. This is the same word which is used in 2 Thessalonians 2:7, and rendered “withholdeth,” except that it is there in the neuter gender. There can be no doubt that there is reference to the same restraining power, or the same power under the control of an individual; but what that was, is not quite certain. It was some power which operated as a check on the growing corruptions then existing, and which prevented their full development, but which was to be removed at no distant period, and whose removal would give an opportunity for these corruptions to develop themselves, and for the full revelation of the man of sin. Such a supposition as that the civil power of Rome was such a restraint, operating to prevent the assumption of the ecclesiastical claims of supremacy which afterward characterized the papacy, will correspond with all that is necessarily implied in the language.