Albert Barnes Commentary Romans 2:23

"thou who gloriest in the law, through thy transgression of the law dishonorest thou God?" — Romans 2:23 (ASV)

Makest thy boast, etc. To boast in the law implied their conviction of its excellence and obligation, as one does not boast of that which one esteems to be of no value.

Dishonourest thou God. By boasting of the law, they proclaimed their conviction that it was from God. By breaking it, they denied it.

And as actions are a true test of people's real opinions, their breaking the law did it more dishonour than their boasting of it did it honour.

This is always the case. It matters little what a person's speculative opinions may be; their practice may do far more to disgrace religion than their profession does to honour it.

It is the life and conduct, and not merely the profession of the lips, that does real honour to the true religion. Alas, how aptly and forcefully this question may be put to many who call themselves Christians!