The Beast is man's government.
The Mark of The Beast, like all scripture, is given so that we may understand God and how to serve Him better. The Mark of The Beast teaches us that the Lord demands uncompromising obedience and unswerving dedication. The Beast represents the archetype of the tyrannical state, which is opposed to God’s Word and God’s Law.
In scripture, the Beast is defined as kings (Daniel 7:17, Revelation 17:10-12), and man-made kingdoms (Daniel 7:18,23, Revelation 16:10) that have power to make war and kill (Revelation 11:7; 17:14). The Beast is the government, with rulers and armies, that are against God and his servants (Revelation 19:19). Jesus said, "He that is not with me is against me" (Matthew 12:30, Luke 11:23). So rulers that enforce laws contrary to God’s Law, are the Beast.
Followers of the Beast receive his mark of ownership; submission to ungodly, anti-Christian law. The mark is an allusion to the Old Testament symbol of man’s total obedience to God, and stands as a warning that a society’s God (whether the true God or the state) demands complete commitment in all areas of life. Christians cannot compromise (2 Cor.6:14-18). The state is not absolute, it’s under authority of Christ (Psalm 2, Matthew 28:18); it’s an instrument of God (Romans 13:1-7). It has no license to do whatever it likes. It's ordained purpose is for a rod of correction; to speak the Word of God, to punish evil, and to reward good (Romans 13:4, 1 Peter 2:14, Hebrews 13:7). That is its only authorized purpose.
Who gives power to the Beast? The dragon (Revelation 13:2,4). Who is the dragon? This dragon is the spirit of satan (Revelation 12:9). Those who have the spirit of satan make war with those who "...keep the commandments of God, and have the testimony of Jesus Christ" (Revelation 12:17). The Lord God has revealed Himself as God, but the spirit of satan is the god and prince of this world (2 Corinthians 4:4 John 12:31).