A frequent misinterpretation of this verse is to see it as teaching salvation or God's favor earned solely by human effort and perfect law-keeping, reducing grace to legalism and ignoring the psalm's overarching theme of God's initiative in mercy; it actually describes the blessed outcome for those already in covenant relationship who respond in faithful living, not a condition for entering that relationship.
Psalms 103:18
King James Version (1769)
18 To such as keep his covenant, and to those that remember his commandments to do them.
The core truth of Psalms 103:18 is that God's merciful compassion and blessings endure across generations specifically for those who uphold His covenant through faithful remembrance and obedience to His commandments, emphasizing a relational commitment where divine favor flows to the obedient heart within the framework of God's gracious promises.