John Calvin Commentary Romans 2:22

"thou that sayest a man should not commit adultery, dost thou commit adultery? thou that abhorrest idols, dost thou rob temples?" — Romans 2:22 (ASV)

You who abhor idols, etc. He suitably compares sacrilege to idolatry, as it is of the same kind. Sacrilege is simply a profanation of the Divine Majesty, a sin not unknown to heathen poets. For this reason, Ovid (Metamorphoses 3) calls Lycurgus sacrilegious for despising the rites of Bacchus; and in his Fasti, he calls those hands which violated the majesty of Venus sacrilegious.

However, as the Gentiles ascribed the majesty of their gods to idols, they only considered it sacrilege when anyone plundered what was dedicated to their temples, in which, as they believed, all of religion centered. So today, where superstition reigns and not the Word of God, they acknowledge no other kind of sacrilege than stealing what belongs to churches, as if there is no God but in idols, and no religion but in pomp and magnificence.

We are warned here: first, not to flatter ourselves and despise others when we have performed only some portions of the law; and secondly, not to glory in having outward idolatry removed while we do not care to drive away and eradicate the impiety that lies hidden in our hearts.