Now, by these words the Apostle shows that there are two parts in Christianity which correspond with the two tables of the Law. Therefore, he who separates the one from the other, has nothing but what is mutilated and mangled. And hence it appears what sort of teachers they are who make no mention of faith, and enjoin only the duty of honesty and uprightness towards men; nay, it is a profane philosophy, that dwells only on the outward mask of righteousness, if indeed it deserves to be called philosophy; for it so unreasonably performs its own duties, that it robs God, to whom the preeminence belongs, of his own rights. Let us then remember, that the life of a Christian is not complete in all its parts, unless we attend to faith as well as to love.
—Calvin, Commentary on Hebrews 6:11