Of all the Psalms, I quote Psalm 103 more than any other. It’s a reflex: the psalm speaks with a grace and beauty to countless moments in life.
The heart of the matter - all the time - is that God is holy, and we are not. God is great and powerful, and we are not. Our lives last for a breath, and He lives forever. This imbalance is great - even infinite. Bridging this distance is the heart of all religion.
In some religions, one is left only with fear - for instance, with the Greeks and their randomly violent pantheon of gods. In other religions, the god is loving and serene, but also plump and impotent - for instance, in the eastern religions. In some religions, the god is far off, powerful and capricious. In others, he is as close as the idol on your shelf - and just as powerful.
Yet the God of the Bible - the God Who is there - is neither only one or the other. This God is supreme, in every way. And yet He condescends to relate to His children with “steadfast love” (in the Hebrew, “qesed”). Both words are true: His love is true and full, and it never ends - full stop. Thus, though our sins stack tall, His steadfast love goes higher (verse 11). Though our lives end quickly, His steadfast love to us extends beyond our lives, to our children’s children (verse 17).
Though He is God, He is not demanding like Zeus. He knows we are but dust.
Now, the question for all the Psalms is, “How do I, a modern non-Jewish reader, get ‘into’ the Psalm? How can I rightly claim all its benefits for myself?” The answer comes in verses 17 and 18: this Psalm is for those who fear him, who keep His covenant, and who remember to keep his commandments. Which, if you are honest with yourself, should leave you disappointed and longing, like a child looking into a toy store window without the means to buy any of it.
This is why God sent His Son. Christ did all this for us, in our place. He then died for our sins, was raised in righteousness and ascended, now occupying God’s throne. Jesus fulfilled this Psalm, for us. We gain entrance into all its benefits by faith in him. In him we declare to ourselves:
“Bless the Lord O my soul!”