“Remember your mercy, O Lord, and your steadfast love, for they have been from of old. Remember not the sins of my youth or my transgressions; according to your steadfast love remember me, for the sake of your goodness, O Lord!” -Psalm 25:6–7
David prays for pardon of his transgressions, particular those sins of his youth. The request of his pardon is not, however, based on any merit of his own but upon the very character of God himself.
He uses zkr (remember) three times, twice in the affirmative in relation to God’s character and once in the negative in relation to David’s sin. “Remember” is not a suggestion that God forgets or can forget in the way that we do; rather, it is a reference to God’s covenant nature and suggests that God fulfill David’s request on the basis of that which he is calling to his attention, namely God’s mercy, steadfast love, and goodness.
For further consideration, consider Thomas Oden’s explanation of God’s righteousness in relation to his goodness and our salvation from our sins:
That God will judge justly in the final judgment is a source of comfort to believers and a call to penitence to those who pervert justice. But there is a sober awareness in the New Testament that all human righteousness falls short of divine righteousness, for “All have swerved aside, all alike have become debased” (Rom. 3:12). The good news is that God has provided the gift of Christ’s righteousness to clothe us in God’s own uprightness in the time of final judgment (Rom. 5:17; John Chrysostom, Hom. on Timothy IV, NPNF 1 XIII, pp. 419–23).
The righteousness of God implies that God’s will is unfailingly determined by God’s goodness (Justin Martyr, On the Sole Government of God, ANF I, pp. 290 ff.; Tho. Aq., ST I Q19, I, pp. 110 ff.). The righteousness of God, therefore, consists simply in the fulfillment of God’s own will as invariably shaped by God’s incomparable goodness, so that God works always in accord with his own good purpose. It is impossible for God to lack righteousness, for righteousness itself is understandable only in relation to God (Theophilus, To Autolycus III.9–12, ANF I, pp. 113 f.). It is impossible for sinners to act aright except by God’s assistance (Justin Martyr, Dialogue with Trypho XCII, ANF I, p. 245; Tho. Aq., ST I–IIae Q56, I, pp. 822 f.).