This was just incredible! And in more than one way I think.
This is the deception of religion which Satan is such a mastermind of arranging. He comes as an angel of light as Paul tells in his epistle to the church at Corinth, which is where the verse in the heading is from. It is verse 4 of the 11th chapter of 2nd Corinthians.
Paul went on to say this in the same chapter:
"And what I do I will continue to do, in order to undermine the claim of those who would like to claim that in their boasted mission they work on the same terms as we do. For such men are false apostles, deceitful workmen, disguising themselves as apostles of Christ. And no wonder, for even Satan disguises himself as an angel of light. So it is no surprise if his servants, also, disguise themselves as servants of righteousness. Their end will correspond to their deeds."
Paul was pastoring this church. he was protecting them from false religion, that was very deceptive. And in our day it may even be much worse, and much more deceptive.
Jesus said, "Beware, and take heed, for there shall be false preachers, teachers, and even christs, who if it were possible, would deceive even God's elect children."