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.
For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. (John 3:16)
The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. (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.
Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils; (1 Timothy 4:1)
This will be carried out, at least in part by false Christs and false prophets similar to those the apostle Paul confronted in his day.
For such [are] false apostles, deceitful workers, transforming themselves into the apostles of Christ. And no marvel; for Satan himself is transformed into an angel of light. Therefore [it is] no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works. (2 Corinthians 11:13-15)
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.
For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if [it were] possible, they shall deceive the very elect. (Matthew 24:24)
[Even him], whose coming is after the working of Satan with all power and signs and lying wonders, (2 Thessalonians 2:9)
And he doeth great wonders, so that he maketh fire come down from heaven on the earth in the sight of men, And deceiveth them that dwell on the earth by [the means of] those miracles which he had power to do in the sight of the beast; saying to them that dwell on the earth, that they should make an image to the beast, which had the wound by a sword, and did live. (Revelation 13:13-14)
For they are the spirits of devils, working miracles, [which] go forth unto the kings of the earth and of the whole world, to gather them to the battle of that great day of God Almighty. (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.