Augustine of Hippo — as excerpted in the Catena Aurea on John 8:31-36

“(super Joan. Tr. xl. 10. et seq.) The first stage of freedom is, the abstaining from sin. But that is only incipient, it is not perfect freedom: for the flesh still lusteth against the spirit, so that ye do not do the things that ye would. Full and perfect freedom will only be, when the contest is over, and the last enemy, death, is destroyed.”