7 Let them take heed, then, who love His gentleness in the Lord, and let them fear His truth. For “The Lord is sweet and right.” You love Him in that He is sweet; fear Him in that He is right. As the meek, He said, “I held my peace;” but as the just, He said, “Shall I always be silent?” “The Lord is merciful and pitiful.” So He is, certainly. Add yet further, “Long-suffering;” add yet further, “And very pitiful:” but fear what comes last, “And true.” For those whom He now bears with as sinners, He will judge as despisers.
“Or do you despise the riches of His long-suffering and gentleness; not knowing that the forbearance of God leads you to repentance? But you, after your hardness and impenitent heart, treasurest up for yourself wrath against the day of wrath and the revelation of the righteous judgment of God; who will render to every man according to his deeds.” The Lord is gentle, the Lord is long-suffering, the Lord is pitiful; but the Lord is also just, the Lord is also true. He bestows on you space for correction; but you love the delay of judgment more than the amendment of your ways.
Have you been a bad man yesterday? Today be a good man. Have you gone on in your wickedness today? At any rate change tomorrow. You are always expecting, and from the mercy of God makest exceeding great promises to yourself. As if He, who has promised you pardon through repentance, promised you also a longer life. How do you know what tomorrow may bring forth? Rightly you say in your heart: When I shall have corrected my ways, God will put all my sins away. We cannot deny that God has promised pardon to those that have amended their ways and are converted. For in what prophet you read to me that God has promised pardon to him that amends, you do not read to me that God has promised you a long life.
Source: Tractates on the Gospel of John (New Advent)