Because God and 2 Peter Say So

11Dear friends, I urge you, as aliens and strangers in the world, to abstain from sinful desires, which war against your soul.

12Live such good lives among the pagans that, though they accuse you of doing wrong, they may see your good deeds and glorify God on the day he visits us.
Submission to Rulers and Masters

13Submit yourselves for the Lord's sake to every authority instituted among men: whether to the king, as the supreme authority,

14or to governors, who are sent by him to punish those who do wrong and to commend those who do right.

15For it is God's will that by doing good you should silence the ignorant talk of foolish men. 16Live as free men, but do not use your freedom as a cover-up for evil; live as servants of God. 17Show proper respect to everyone: Love the brotherhood of believers, fear God, honor the king president.