John Wesley on Romans 11:33

O the depth of the riches, and wisdom, and knowledge of God - In the ninth chapter, St. Paul had sailed but in a narrow sea: now he is in the ocean. The depth of the riches is described, Ro 11:35; the depth of wisdom, Ro 11:34; the depth of knowledge, in the latter part of this verse. Wisdom directs all things to the best end; knowledge sees that end. How unsearchable are his judgments - With regard to unbelievers. His ways - With regard to believers. His ways are more upon a level; His judgments "a great deep." But even his ways we cannot trace.