This is why I believe this is True !
2 Thess 2:1-4
1Now we beseech you, brethren, by the coming of our Lord Jesus Christ, and by our gathering together unto him,
2That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand.
3Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;
4Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God.
Isa 14:13-14
13For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north:
I will ascend above the heights of the clouds; I will be like the most High.
Man's own freewill by far is the most believed and popular religious conviction throughout the whole world. Rev 13:1;5-8
1And I stood upon the sand of the sea, and saw a beast rise up out of the sea, having seven heads and ten horns, and upon his horns ten crowns, and upon his heads the name of blasphemy.
5And there was given unto him a mouth speaking great things and blasphemies; and power was given unto him to continue forty and two months.
6And he opened his mouth in blasphemy against God, to blaspheme his name, and his tabernacle, and them that dwell in heaven.
7And it was given unto him to make war with the saints, and to overcome them: and power was given him over all kindreds, and tongues, and nations.
8And all that dwell upon the earth shall worship him, whose names are not written in the book of life of the Lamb slain from the foundation of the world.
It's adherents are linked to all the various denominations, and sects, yes, even the non religious adhere to man's freewill.
So John writes Rev 13:16
And he causeth all, both small and great, rich and poor, free and bond, to receive a mark in their right hand, or in their foreheads:
That is all follow this deadly concept or philosophy of man's freewill !