So David reigned over all Israel; and David administered justice and righteousness for all his people.
2 Samuel 8:15
David’s beginning as a ruler is amazing. He behaves righteously and administers justice and is beloved by the people. He is in love with God and passionate about serving God and God’s response is to give David success wherever David turns. David wins battles and wars; makes peace all over the place; brings the Ark into Jerusalem; gets the materials together to build the temple. God’s favor in David’s life is obvious. Later, a prophet would communicate to Israel what God’s desire for people is and it reduces to doing justly, loving mercy, and walking humbly with God. David was doing all of this.
David ruled over Israel. He ruled over what God has given him to rule. God has given me self-control as a gift of the Spirit so that I might rule myself. God places me in positions of authority from time to time and I am expected—by God—to administer justice and righteousness in those positions. If I am obedient, then God is free to bless me and, more importantly, to bless the thing over which He has given me authority. These things include the ones that are probably obvious to most believers: my body, my finances, my family, and my work. I am to treat my body as the temple of God—no defiling the temple by bringing in images that should not be there. I am to be a steward of the finances God gives me; to invest in God’s kingdom and spend according to His priorities. I am to be the head of my family and to lead them as God leads me. Contrary to what some might think, this does not mean I go all authoritarian and start handing out commandments, although kids need that sort of thing every now and then. To lead as God leads is to lead by example. God expects obedience, so Jesus came down and made Himself obedient to the point of dying on the cross. God expects us to love one another, so Jesus came down to love on people and show us what love looks like. That is leading as God leads: getting out front and doing the thing that I expect to be done. I am to treat my work as a blessing. God created men to work—Adam was told to tend the Garden of Eden, so agriculture was the first occupation—and having work to do is a blessing. I learned this during a period of unemployment. Am I ruling the things over which God has given me authority in God’s way? If not, then that needs to be corrected. If so, then I need to continue in that.