During the Great Tribulation, the spirit of lawlessness will continue to work through the Antichrist to deceive people.
2 Thessalonians 2:7,9-12 (authorized KJV):
"For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
9 even him, whose coming is after the working of Satan with all power and signs and lying wonders, 10 and with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved. 11 And for this cause God shall send them strong delusion, that they should believe a lie: 12 that they all might be damned who believed not the truth, but had pleasure in unrighteousness."
2 Thessalonians 2:7,9-12 (NLT):
"For this lawlessness is already at work secretly, and it will remain secret until the one who is holding it back steps out of the way.
9 This man will come to do the work of Satan with counterfeit power and signs and miracles. 10 He will use every kind of evil deception to fool those on their way to destruction, because they refuse to love and accept the truth that would save them. 11 So God will cause them to be greatly deceived, and they will believe these lies. 12 Then they will be condemned for enjoying evil rather than believing the truth."