Moral virtue is, indeed, the best thing amongst men that is of them. It far exceeds in worth, use, and satisfaction, all that the honours, powers, profits, and pleasures of the world can extend unto. And it is admirable to consider what instructions are given concerning it, what expressions are made of its excellency, what encomiums of its use and beauty, by learned contemplative men among the heathen; the wisest of whom did acknowledge that there was yet something in it which they could only admire, and not comprehend. And very eminent instances of the practice of it were given in the lives and conversations of some of them; and as the examples of their righteousness, moderation, temperance, equanimity, in all conditions, rise up at present unto the shame and reproach of many that are called Christians, so they will be called over at the last day as an aggravation of their condemnation. But to suppose that this moral virtue, whatever it be really in its own nature, or however advanced in the imaginations of men, is that holiness of truth which believers receive by the Spirit of Christ, is to debase it, to overthrow it, and to drive the souls of men from seeking an interest in it.
John Owen, Pneumatologia, IV.1