Infused righteousness means that God imparts grace to a person so that this person can do good works. This particular understanding of grace arose in order to shut down any possible pelagian theology: Pelagians believe that by nature people can do good works that God looks upon with favour.
But if we can do good works by nature and so enter into God’s favour, that produces a twofold problem: first it denies that we are by nature sinners; second it makes our good works apart from grace meritorious before God. But the Bible denies both.
So faithful Christians used the language of infused righteousness to indicate that initial justification could only happen through the grace of God and not through any good thing in us.
And yet infused righteousness came with its own liabilities. It confuses biblical categories because it entails that justification is a process of grace. It suggests that justification and sanctification are indistinguishable.
When unscrupulous theologians got a hold of this teaching, they did not have the requisite balance to integrate this idea into an overarching biblical system.
So infused righteousness basically gave the grace to obey God to earn merit, which could be lost after gaining it in baptism. The sacrament of penance then restored grace—at least for venial sins.
The whole system relies on a system of credit and debt. It makes justification an imperfect process.
Martin Luther and the Reformers saw this. Denying this credit-debt system, they affirmed that justification means a declaration of God: it means God remits our sins and imputes Christ’s righteousness.
It is not a process that can be stopped; but a final declaration given only by faith. Something that cannot ever be lost. It unburdened the conscience because people no longer had to maintain their justification by their own works in cooperation with God’s grace.
Justification for Roman Catholics, then, lies within our power to earn and maintain. For the Reformers, it lies entirely in Christ. It is alien to us. Accomplished in him for us. We do nothing to earn it or maintain it. It is free.
But that’s that’s the difference between the Gospel of Christ and the Gospel of religion. Salvific grace means that Christ becomes ours totally. He imputes his righteousness to us. God declares is just for Christ’s sake, not ours. No merit to be gained or work to be done; no fear of loss; no system of penance. Only accepting the gift of God.
If you’ve ever felt depressed or down because of your sin or lack of Christian progress, you evince a reliance on infused righteousness. Your sin or lack thereof means nothing to your justification. It’s done in Christ outside of you. It’s given to you as a declaration.
Yes, faith always produces love. So works follow—but they are not the basis of justification nor the mark of assurance. That’s the Gospel of the Reformation. Christ alone for us alone to save us alone by faith alone.