The sheer wonder and wisdom of these processes of overflowing grace now fills him with praise. God has chosen to make grace so attractive that those who have not received it will be envious of those who have.
Oh, the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgments and how inscrutable his ways!
“For who has known the mind of the Lord,
or who has been his counsellor?” (Isa 40:13)
“Or who has given a gift to him
that he might be repaid?” (Job 41:11)
For from him and through him and to him are all things. To him be glory forever. Amen.
This exclaimation of praise sums up the doctrines of grace in the whole letter. ‘Oh, the depth (inexhaustibility) of the riches’ (2:4 ‘the riches of his kindness’; 9:23 ‘the riches of his glory’) ‘and wisdom and knowledge of God! (in planning to save so many in such a wonderful way). ‘How unsearchable his judgements’ (that is, the way he runs the world) ‘and his paths beyond tracing out!’ Paul stands amazed at the wonder of overflowing grace. No human being inventing a religion would have got anywhere near the beauty of grace.
He backs this up first from Isaiah 40:13, where Isaiah marvels at God’s future grace in bringing the people up from Babylon, looking further forward to the wonder of the forgiveness of sins. ‘Who has known the mind of the Lord? Or what has been his counsellor?’ No one is wiser than God. He has never needed to advertise for a management consultant to help him rule and rescue the world.
And then he quotes God’s own second speech to Job: ‘Who has ever given to God, that God should repay him?'(Job 41:11). Faced with the awesome terror of the evil universe (Leviathan included) is able to make any claim on God, to say to God, ‘You own me one’. God is the source of all power and all grace.
‘For from him’ (since he is the source of all) ‘and through him’ (for he is the sustainer of all) ‘and to him’ (for he is the goal of all creation) ‘are all things. To him be the glory forever! Amen.’ This is the doctrinal message of Romans. All of salvation, from its origin in eternity to its consummation in the New Creation, is of grace alone by the sacrifice of Christ alone, mediated to human beings by the Spirit of God alone, received empty-handed by faith alone. And because it is all without any exception from grace, it is all without any exception to his glory.
-Christopher Ash, Teaching Romans, p.136