The Bible as a story of God's covenants with man shows us the norms and structure by which we are to live. The Bible can also be told as the story of the kingdom of God, showing us the historical situation we find ourselves in. God takes millennia to fulfill His purposes, not according to the timeline of human kings.
We live in two ages. The present age will pass away at Christ's return, but for now sin is still present and people live without thought of God. The coming kingdom of Christ is already here since His resurrection, but not yet fulfilled. So this is a time of suffering for the church, but also victory.
God is king and lord of His kingdom (Ex 15:18; Ps 93-99; 1 Sam 8:7). The ark is His throne. Jesus is God's appointed king of his kingdom (Ps 2), the greater King than David (Matt 22:41-46), who told Pilate he was a king and welcomed the crowd's praises as their king at His triumphal entry. He has all authority as the highest king of all kings (Phil 2:9-11; Matt 28:18; Rev 19:16). Now that He ascended, His people carry on His kingdom work in evangelism, discipleship, cultural and social change, seeking to bring all the world to keep His ways in all things.
Heralds announce good news in God's kingdom - the Gospel of God's favor to us in Christ's death and resurrection. God's vengeance on His rebellious enemies is part of His Kingdom work. Proclaiming God's law is also important. We aren't saved by keeping it, but it does more than drive us to Christ for having broken it. It also shows us how to live in the present and future.
There is not a kingdom of law (the state) ruled by a religiously neutral natural law, and a kingdom of grace/gospel (church). There is one kingdom of God, and the social order beyond the church either acknowledges and submits to God or it doesn't. Modern secular society is not neutral in religion, but rebellious against the true God. [Another way of saying this: God is not okay with governments trying to be neutral regarding Him. He expects kings to bend the knee to Him in this world (Ps 2:10-12).]
Jesus describes kingdom life in the sermon on the mount. The church is kingdom headquarters, but isn't the boundary of the kingdom. The kingdom has deeply shaped human cultures in the past, as it should.