For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way. And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming: Even him, whose coming is after the working of Satan with all power and signs and lying wonders, And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved. And for this cause God shall send them strong delusion, that they should believe a lie: That they all might be damned who believed not the truth, but had pleasure in unrighteousness. (2 Thessalonians 2:7-12)
This is a sobering passage. The truth is that God offers eternal life to anyone who believes in Jesus Christ (John 3:16, 2 Peter 3:9). But because of man’s rejection of the only way of salvation through His Son, Jesus Christ, God will send a strong delusion. This will occur primarily through seducing spirits and doctrines of devils (1 Timothy 4:1), false Christs, and false prophets. In 2 Corinthians 11:13-15 the apostle Paul gives a similar description of the false apostles that he confronted in his day.
Demonic activity and deception will increase as the second coming of Jesus Christ approaches. One of the primary means of deception is through signs and wonders, and miracles (Matthew 24:24, 2 Thessalonians 2:9, Revelation 13:13-14, revelation 16:14). While this deception or delusion is directed at unbelievers as a consequence for their unbelief as stated above, believers can be drawn into it as well. This is why Jesus and the New Testament writers warn us so many times about deception. When describing the end times, the first words out of Jesus’ mouth are “see that no one deceives you”. If His disciples could not be deceived, He would not have warned them.
Keep in mind that there is no Scripture that indicates that signs and wonders, and miracles from God’s people will increase during this same period of time.