A great temptation for any Christian is to think only in terms of one kingdom. The idea that we live in two kingdoms at the same time is impossible for us to represent in our minds because we aren’t naturally wired to think this way. It’s for this reason that we can’t grasp what it means to be justified and sinful at the same time. We are inclined to always think in terms of progressing gradually toward a goal. This is the allure of progressive sanctification: I am partially righteous and partially sinful; but if I focus on my good works, hopefully my righteousness begins to outweigh my sinfulness.
Even Augustine, the greatest of the church fathers, could only imagine growth in God’s grace as a gradual process or a journey toward the blessing of eternal life. In fact, it’s this tendency of ours to think in terms of only one kingdom that rationalized the emerging doctrine of purgatory in the medieval church. If at death, sin remains, then purgatory “purges” the remnants of sin. Only the holiest of people – those canonized by the Roman Catholic Church as saints – enter into heavenly blessing immediately upon death.
Luther’s break with Augustine cleared the way for thinking rightly about what it means to be a justified sinner. It also helped set straight the Christian view of politics. Augustine’s greatest insight was the supremacy of God’s grace. God elects believers out of sheer mercy. But grace is also, for Augustine, a power at work transforming the Christian into the image of Christ in holiness.
Luther’s break with Augustine cleared the way for thinking rightly about what it means to be a justified sinner. It also helped set straight the Christian view of politics
Where Augustine emphasizes grace, Luther emphasizes faith grasping a promise from God. A promise isn’t a power infused into the soul which conforms it to divine love which then works itself out in righteous deeds. The promise, according to Luther, delivers all the blessings of which it speaks. Faith comes by hearing (Rom. 10:17) and trusts the power of God’s word to give what God says. Justification is by faith alone, not works, because salvation is a matter of trust rather than work (Rom. 4:5).
Sin and righteousness aren’t on a sliding scale, as if one could have some of both to one degree or another. Sin and righteousness are total realities. There’s an absolute break between them. Luther’s doctrine of justification is incoherent without this logic, which theologians call the simul (simultaneously righteous and sinful). Progressive sanctification can only think in terms of one kingdom where righteousness gradually captures territory in human hearts.
Sin and righteousness aren’t on a sliding scale, as if one could have some of both to one degree or another. Sin and righteousness are total realities. There’s an absolute break between them
Luther’s view of the simul permits no progress in holiness because there is no more progress to be made. Faith possesses all the blessings of God’s promise, though hidden from sight. Christian living is therefore a matter of dying daily to the old sinful self. And in the old world, God will use the law to exact something from the old nature for the sake of the neighbor. Truly good works come forth from faith alone, and remain hidden – especially from the Christians who do them!
Luther’s view of the simul permits no progress in holiness because there is no more progress to be made
The implications of this for how Christians engage politics might be opaque at this point. But there is a crucial way in which Luther’s simul and the two kingdoms intersect. Luther’s simul explains how Christians are totally righteous and totally sinful at the same time. The two kingdoms doctrine likewise distinguishes God’s two ways of dealing with the world. God governs the conscience through the gospel and its proclamation while he governs the old world with the law.
We can now make our proper distinctions. The believer is saint and sinner, and so is the church. When the church proclaims the gospel, it carries out its proper work. When the church drafts a constitution, registers as a non-profit with the state, and pays for the heat, the church is operating in the realm of the law. The church must preach the law, but for sin’s judgment unto Christ. The church isn’t the enforcer of the law.
God governs the conscience through the gospel and its proclamation while he governs the old world with the law
The two kingdoms doctrine is a commonplace of the Reformation tradition, shaping the political theology of both Lutheranism and classic Reformed theology. This doctrine is a safeguard against confusing law and gospel especially when it comes to politics. However, two kingdoms theology has been criticized for its tendency to bless existing political authority even when it’s abused. Often this criticism masks a desire for the church to become a political animal and go beyond the preaching of law and gospel.
Some are even more ambitious, thinking that the church is the only true political institution there is. In America, this is a particularly strong temptation. Ronald Reagan famously addressed the nation the night before the 1980 election using the Sermon on the Mount: “You are the light of the world. A city set on a hill cannot be hidden” (Matt 5:14). But it’s not only the right side of the political spectrum that dreams of the church involving itself in politics. The whole social gospel movement in the early twentieth-century was a product of mainline liberal churches, and united itself with the emerging progressive movement on the American left.
It's true that God has established political authority and that Christians, like everyone else, should obey it (Rom 13:1–7). It’s also true that God wills that the governing authorities act justly. Injustice and the abuse of power are by no means insignificant. But to correct injustice, society requires competent people carrying out their ordinary vocations to establish order and justice. While it might be tempting for the church to employ its “prophetic voice” in the face of injustice, this fundamentally confuses law and gospel. It is an instance of one-kingdom thinking that obscures the forgiveness of sins given freely in Jesus Christ.
The two kingdoms doctrine presents a great challenge to Christians aligned with both the left and the right. On the left, it seems that the church sidelines itself from righteous causes that benefit the poor and oppressed. On the right, the two kingdoms doctrine is challenging especially given that modern Western society permits (or promotes) moral degradation in abortion, homosexual marriage, pornography, and gender ideology.
The two kingdoms doctrine presents a great challenge to Christians aligned with both the left and the right
It is for the civil, political realm to litigate how to alleviate poverty, uphold law and order, and promote the causes of life and the traditional family. Despite our persistent desire to think in terms of only one kingdom, the church preaches the law for judgment and the gospel for righteousness. The church cannot become a political actor or a unique society without obscuring its greatest treasure, which is the promise of free forgiveness in Christ.