"That the abilities of man are equal to the precepts of the divine
law, has long been a common idea, and has some show of plausibility.
It is founded, however, on the grossest ignorance of the law. Those
who deem it a kind of sacrilege to say, that the observance of the law
is impossible, insist, as their strongest argument, that, if it is,
the law has been given in vain. For they speak just as if Paul had
never said anything about the Law. But what, pray, is meant by
saying, that the Law, "was added because of transgressions;" "by the
law is the knowledge of sin;" "I had not known sin but by the law;" "
the law entered that the offense might abound."? (Gal. 3:19, Rom.
3:20, 7:7, 5:20) Is it meant that the Law was to be limited to our
strength, lest it should be given in vain? Is it not rather meant
that it was placed far above us, in order to convince us of our utter
feebleness? Paul indeed declares, that charity is the end and
fulfilling of the Law (1 Tim. 1:5). But when he prays that the minds
of the Thessalonians may be filled with it, he clearly enough
acknowledges that the Law sounds in our ears without profit if God does
not implant it thoroughly in our hearts (1 Thess. 3:12)"
From Calvin's Institutues, p. 278: