2 Thessalonians 2:1-4

YLT(i) 1 And we ask you, brethren, in regard to the presence of our Lord Jesus Christ, and of our gathering together unto him, 2 that ye be not quickly shaken in mind, nor be troubled, neither through spirit, neither through word, neither through letters as through us, as that the day of Christ hath arrived;
3 let not any one deceive you in any manner, because—if the falling away may not come first, and the man of sin be revealed—the son of the destruction, 4 who is opposing and is raising himself up above all called God or worshipped, so that he in the sanctuary of God as God hath sat down, shewing himself off that he is God—the day doth not come .