Romans 2:18

His will. That is, God’s will.

Approvest. Gr. dokimazo, “to test,” “to prove,” “to discern” (see Rom. 12:2; 1 Cor. 3:13; 11:28; 2 Cor. 8:8), or “to approve” as the result of testing (see Rom. 14:22; 1 Cor. 16:3; 1 Thess. 2:4).

Things that are more excellent. Literally, “things that differ”; hence, things that are excellent, from the point of view of one who approves of them. This passage refers either to the ability of the Jews to discriminate by means of the law between good and evil, or to the fact that the Jews actually approved, in theory, the things that excel. They were proud of this refinement of their moral sensibilities, as if mere approval without obedience constituted righteousness. It is clear that Paul is preparing to contrast the spiritual enlightenment of the Jews with their spiritual failure (vs. 21-24).

Instructed. Gr. katecheo. The verb occurs in the papyri with the connotation of legal instruction. Compare its use in Luke 1:4; Acts 18:25; 1 Cor. 14:19; Gal. 6:6. Katecheo is the source of our English “catechize.” The Jews were carefully instructed in the teachings of the law in their youth, and for the rest of their lives listened to the regular reading and exposition of the OT.