Romans 2:18

And knowest his will
Not the secret will or purpose of God; nor his revealed will in the Gospel, for of this they were ignorant; but his declared will in the law, showing what is to be done, and what is not to be done: to know which in express terms was a privilege, that other people had not; but then the bare knowledge of this will be of no avail: for persons may know their Lord's will, as the Jews did, and not do it, and so be worthy to be beaten with many stripes:

and approvest the things that are more excellent:
or "triest the things that differ"; from one another, and from the will and law of God; or as the Syriac, "discernest" (atylw) , "things that are convenient"; agreeable, which are fit and ought to be done: and having tried and discerned them, they approved of them in their judgment as the things more excellent; but then they did not put these excellent things in practice which they approved of; and the knowledge and approbation they had of these things, arose from their

being instructed out of the law,
and not the Gospel; for the excellent things of the Gospel, they had no discerning, knowledge and approbation of; see ( Philippians 1:10 ) .