Prologue

[1] The Apostle points out two contentious [desires] by these words: the spirit, he says, strives against the flesh and the flesh against the spirit (Gal 5:17), and yet sin arises from both: sometimes it arises from the weakness of the flesh and at other times through ignorance of the spirit; therefore the Apostle says to the Corinthians: let us cleanse ourselves from every defilement of body and spirit (2 Cor 7:1). And just as sin arises from the flesh, out of the weakness of the flesh, thus in Matthew: the spirit indeed is willing, but the flesh is weak (Matt 26:41), so the sin of the spirit arises through ignorance of the spirit, namely when the spirit is deceived. And so on this Sunday we are strengthened against both kinds of sin. We are strengthened against that sin which arises from the weakness of the flesh by the words of the Apostle who says in his letter: we are debtors to the flesh, not so that we may live according to the flesh (Rom 8:12); and we are strengthened against sin that arises from the deception of the spirit, where it says in the Gospel: beware of false prophets, etc. (Matt 7:15).

[2] Let us ask our Savior, who wished us to be wary against both kinds of sin, to grant me something to say which that will be to his honor, etc.