When a person happens to perform a good deed, God accepts it and as a reward for the good deed God pours charity into that person.
 Martin Luther, Commentary on the Epistle to the Galatians (1535). copy citation

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Author Martin Luther
Source Commentary on the Epistle to the Galatians
Topic charity God
Date 1535
Language English
Reference
Note Translated by Theodore Graebner
Weblink http://www.gutenberg.org/files/1549/1549-h/1549-h.htm

Context

“By sacrificing His Son for us God revealed Himself to us as a merciful Father who donates remission of sins, righteousness, and life everlasting for Christ's sake. God hands out His gifts freely unto all men. That is the praise and glory of His mercy. The scholastics explain the way of salvation in this manner. When a person happens to perform a good deed, God accepts it and as a reward for the good deed God pours charity into that person. They call it "charity infused." This charity is supposed to remain in the heart. They get wild when they are told that this quality of the heart cannot justify a person. They also claim that we are able to love God by our own natural strength, to love God above all things, at least to the extent that we deserve grace.” source