"Catholics and Lutherans both agree grace is undeserved and entirely all God’s doing. How God does it is where the wheels spin off the rails. Catholics held to a”infusion” of grace, Lutherans to an “imputation.” Either way, the same source, God.
Infusion of grace enables sinners to cooperatively “grow” toward God through lives transformed in Christ. Imputation of grace declares you’re never going to be any more righteous than you are at the moment Christ declares you his. Nonetheless, both Catholics and Lutherans hold to the doctrine of sanctification, growth in holiness.
In a sense, Catholics conflate justification and sanctification. For Lutherans, sanctification rises as one gains greater awareness of being justified. Now, for the life of me I can’t tell a whole lot of difference one from the other – justification is through Christ by faith that we may ever become who we are, children of God. But in the rarefied airs of theology-talk, Lutherans accused Roman Catholics of believing that humans can earn salvation, and Roman Catholics accused Lutherans of believing that Christians do not need to have their lives transformed. Neither, examined attentively, is what the other actually taught.
A Waffle House waitress explained it to me when I once – and never since – tried to order grits. Grits are like grace, you know. “Honey, you don’t order grits, they just comes.” Now, does it matter how I eat them when they arrive, mixed with my scrambled eggs, or take them straight from the bowl?""