When, under the guidance of the Law, we have advanced thus far, we must, under the same guidance, proceed to descend into ourselves. In this way, we at length arrive at two results: First, contrasting our conduct with the righteousness of the Law, we see how very far it is from being in accordance with the will of God, and, therefore, how unworthy we are of holding our place among his creatures, far less of being accounted his sons; and, secondly, taking a survey of our powers, we see that they are not only unequal to fulfill the Law, but are altogether null. The necessary consequence must be, to produce distrust of our own ability, and also anxiety and trepidation of mind. Conscience cannot feel the burden of its guilt, without forthwith turning to the judgment of God, while the view of this judgment cannot fail to excite a dread of death. In like manner, the proofs of our utter powerlessness must instantly beget despair of our own strength. Both feelings are productive of humility and abasement, and hence the sinner, terrified at the prospect of eternal death (which he sees justly impending over him for his iniquities), turns to the mercy of God as the only haven of safety. Feeling his utter inability to pay what he owes to the Law, and thus despairing of himself, he rethinks him of applying and looking to some other quarter for help.
– From The Institutes of the Christian Religion, Book 2 – Chapter 8.