2 Thessalonians 2:3; 2 Thessalonians 2:4

3 Do not let anyone deceive you in any way. For the Day will not come until the final Rebellion takes place and the Wicked One appears, who is destined to hell.

4 He will oppose every so-called god or object of worship and will put himself above them all. He will even go in and sit down in God's Temple and claim to be God.