The Lord Reigns!

That the God of Israel is king of the cosmos is certainly one of the most prevalent teachings in the whole of Scripture. Even the Law teaches us God is Sovereign: earthly lords enact legislation for their people, how much more will the Lord of the Universe?
When reflecting on His reign, God's total sovereignty is one of the foremost topics of the Bible. Nothing happens apart from His sovereign decree, not even the smallest detail.

Prov 16:33 The lot (or die) is cast into the lap, but its every decision is from the Lord.

There is no plan or scheme of Man that can thwart His will.

Job 42:2 I know that God can do all things, and that no purpose of His can be thwarted.

Ps 135:6 For I know that the Lord is great, and that our Lord is above all gods. Whatever the Lord pleases, He does, in heaven and on earth, in the seas and all deeps.

All humans (even the best acting humans) rebel against His reign yet He knows their intent and actions before they do (before they're even born) and intends even their actions to shape His Story of Redemption.
That God is completely sovereign remains unbelievable to the unregenerate as they see finitely (and without the eyes of faith) and without God's overview toward fulfilling His ultimate ends.
In Adam, all were with him (our first father) choosing to exert ourselves selfishly - chasing after our own desires - to remove Him from His throne and place ourselves in His place.

Rom 5:12 Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned—Rom 5:15-17 But the free gift is not like the trespass. For if many died through one man's trespass, much more have the grace of God and the free gift by the grace of that one man Jesus Christ abounded for many. And the free gift is not like the result of that one man's sin. For the judgment following one trespass brought condemnation, but the free gift following many trespasses brought justification. For if, because of one man's trespass, death reigned through that one man, much more will those who receive the abundance of grace and the free gift of righteousness reign in life through the one man Jesus Christ.

Only once the Lord has set His grace on us, can we recapture the obedience of Eden (before the fall) and start living a life of good works toward our biological families, fellow believers (our new family) and among our neighbors of this world. Much like the good kings of the Old Covenant with Israel they were not to lead men to dwell on their own glory but to point to the Glory of God in Heaven. 

David says, 1 Chron 16:31,34 Let the heavens be glad, and let the earth rejoice, and let them say among the nations, “The Lord reigns!” Oh give thanks to the Lord, for He is good;for His steadfast love endures forever!

 That God is Sovereign over us (and over all) is a comfort to the believer, especially in temptations and trials.