9 “Lead us not into temptation:” forgive what we have done already, and grant that we may not commit any more sins. For whosoever is overcome by temptation, commits sin. Thus the Apostle James says, “Let no man say when he is tempted, he is tempted of God, for God cannot be tempted with evil, neither tempts He any man. But every man is tempted, when he is drawn away of his own lust, and enticed. Then lust, when it has conceived, brings forth sin: and sin, when it is finished, brings forth death.” Therefore that you be not drawn away by your lust; consent not to it.
It has no means of conceiving, but by you. You have consented, hast as it were in your heart admitted her embrace. Lust has risen up, deny yourself to her, follow her not. It is a lust unlawful, impure, and shameful, it will alienate you from God. Give it not then the embrace of your consent, lest you have to bewail the birth; for if you consent, that is, when you have embraced her, she conceives, “and when lust has conceived, it brings forth sin.” Do you not yet fear? “Sin brings forth death;” at least, fear death.
If you fear not sin, yet fear that whereunto it leads. Sin is sweet; but death is bitter. This is the infelicity of men; that for which they sin, they leave here when they die, and the sin themselves they carry with them. Thou dost sin for money, it must be left here: or for a country seat; it must be left here: or for some woman's sake; she must be left here; and whatsoever it be for which you sin, when you shall have closed your eyes in death, you must leave it here; yet the sin itself which you commit, you carry with you.
Source: Sermons on Selected Lessons of the New Testament (New Advent)