Daily Sin Means Daily Repentance

He saved us, not because of works done by us in righteousness, but according to His own mercy.
TITUS 3:5
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Daily Sin Means Daily Repentance
In this life on earth it is impossible for us to live without any sin and defect (even if we have already received grace and the Holy Spirit) because of our sinful, corrupt flesh and blood. This does not cease to be active in evil lusts and desires against God's Commandments until the grave, even in the saints, even though, after they have received grace, they refrain from and guard against sin and oppose the evil lusts, as repentance requires. Therefore, they also still daily need forgiveness, just as they also daily repent because of those remaining defects and weaknesses. They recognize that their life and works are still sinful and would merit God's wrath, if they were not forgiven and covered for Christ's sake. For that reason Christ has established His kingdom on earth which should be called an eternal kingdom of grace and always remain under the forgiveness of sins. Upon those who believe it, it is so powerful that, even though sin is still stuck and so deeply rooted in their flesh and blood that it cannot at all be swept out in this life, nevertheless it shall do no harm but shall be forgiven and not imputed, as long as we remain in the faith and daily work at suppressing the remaining evil lusts until they are entirely blotted out through death and decay in the grave with this old maggot sack, so that the man may rise completely new and pure to eternal life.

From the Church Postil, sermon for Easter Tuesday on Luke 24:36-47 (Luther's Works 77:98-99)