By this grace such is the liberty they receive, that although as long as they live here they have to fight against the lusts of sins, and are overtaken by some sins for which they must daily pray, “Forgive us our debts,” yet they no longer serve the sin which is unto death, of which the apostle John saith, “There is a sin unto death, I do not say that he shall ask for that.” Concerning which sin (since it is not expressed) many different opinions may be formed: but I affirm that sin to be the forsaking until death the “faith which worketh by love.”
Reproduced in full. Translation: Nicene and Post-Nicene Fathers, series 1, vol. 7 (Schaff, 1888), public domain (Public domain).