Satan has deceived the whole world through people’s religion.
Revelation 12:9, “And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.”
The Muslim, Hindu, Buddhist, and other religions do not believe in Jesus Christ; the only name by which you can be saved.
Many Christians are deceived by false ministers. Jesus tells us many will come in His name saying He is Christ deceiving many by perverting the gospel.
Matthew 24:5, “For many shall come in my name, saying, I am Christ; and shall deceive many.”
Matthew 7:15, “Beware of false prophets, which come to you in sheep’s clothing, but inwardly they are ravening wolves.”
II Corinthians 11:12-15, (Paul) “But what I do, that I will do, that I may cut off occasion from them which desire occasion; that wherein they glory, they may be found even as we. 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.”
The time will come when men will not listen to sound doctrine. They will surround themselves with teachers that tell them things they want to hear. Men will turn away from the truth and believe fables.
II Timothy 4:3-4, “For the time will come when they will not endure sound doctrine; but after their own lusts shall they heap to themselves teachers, having itching ears; And they shall turn away their ears from the truth, and shall be turned unto fables.”
Beware of false ministers is what Paul means in II Corinthians 11:3-4.
II Corinthians 11:3-4: “But I fear, lest by any means, as the serpent beguiled Eve through his subtilty, so your minds should be corrupted from the simplicity that is in Christ. For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him.”
Paul fears that if a false minister comes preaching another Jesus (“But I fear”) that you might believe him (“ye might well bear with him”).