2 Thessalonians 2:7-8

v7: Even though the man of lawlessness is yet to be revealed, the spirit of lawlessness is already at work. "While the apostles were still living, the enemy came, and sowed tares; there were then the deeds of the Nicolaitans, people who claimed zeal for Christ but actually opposed him. Pride, ambition, and worldly interests of church pastors and church rulers, such as in Diotrephes and others."  Much of this sinful behaviour, which is still present today in the church, is "concealed from the common view and observation."

v8: We can be certain that the man of lawlessness will come to ruin.  He will be totally and finally destroyed when Jesus returns.