and [if you claim to] know His will and approve the things that are essential or have a sense of what is excellent, based on your instruction from the Law,

Well then, are we [Jews] better off than they? Not at all; for we have already charged that both Jews and Greeks (Gentiles) are under the control of sin and subject to its power.

One person regards one day as better [or more important] than another, while another regards every day [the same as any other]. Let everyone be fully convinced (assured, satisfied) in his own mind.