1) Since the mark is given by the beast then establishing the identity of the beast is crucial to understanding how to avoid the mark.
2) 666 is the number of a man which is associated or a representative of the beast.
3) Those who worship Jesus Christ as Creator DO NOT get the mark. Revelation 14:7 “Saying with a loud voice, Fear God, and give glory to him; for the hour of his judgment is come: and worship him that made heaven, and earth, and the sea, and the fountains of waters.”
4) Those that worship the Beast DO receive the mark and God’s wrath. Revelation 14:9 “And the third angel followed them, saying with a loud voice, If any man worship the beast and his image, and receive his mark in his forehead, or in his hand,”
5) Those that keep God’s Commandments DO NOT receive the mark and avoid the wrath of God. Revelation 14:12 “Here is the patience [endurance/tribulation] of the saints: here are they that keep the Commandments of God, and the faith of Jesus.”
6) 666 is NOT the mark of the beast. 666 is the number of his name. Revelation 13:17 “And that no man might buy or sell, save he that had the mark, OR the name of the beast, OR the number of his name.”
7) The mark of the beast is a counterfeit to the mark or seal of God.