The Reformation admittedly recognized the supernatural character of revelation but nevertheless in fact brought about a great change. In the case of Rome, the mysteries are incomprehensible, primarily because they belong to another, higher, supernatural order, which surpasses the human intellect as such… But the Reformation replaced this contrast between the natural and the supernatural order by that of sin and grace. It located the essence of mystery, not in the fact that it is incomprehensible to human beings as such but to the intellect of the “natural” (i.e., unspiritual) person… But believers do know those mysteries; they are no longer a folly and an offense to them; they do marvel at God’s wisdom and love manifest in them. “The secret of God ought to produce earnest people, not hostile ones” (Augustine). It does not even occur to them, therefore, that the mysteries surpass their reason, that they are above reason; they do not experience them as an oppressive burden but rather as intellectual liberation. Their faith turns into wonder; knowledge terminates in adoration; and their confession becomes a song of praise and thanksgiving. Of this kind, too, is the knowledge of God theology aims for. It is not just a knowing, much less a comprehending; it is better and more glorious than that: it is the knowledge which is life, “eternal life” (John 17:3).
Reformed Dogmatics Vol. 1: Prolegomena (Grand Rapids, Michigan; Baker Academic; 2003) p. 620-21.