"Theology is not merely distinguished from the other sciences by its object, but that it also sustains an altogether unique relation to this object, for which no strict analogy can be found elsewhere. In all the other sciences man is the one who of himself takes the first step in approaching the objective world, in subjecting it to his scrutiny, in compelling it to submit to his experiments — in a word, man is the one who proceeds actively to make nature reveal her facts and her laws.
"In Theology this relation between the subject and object is reversed. Here it is God who takes the first step to approach man for the purpose of disclosing His nature, nay, who creates man in order that He may have a finite mind able to receive the knowledge of His infinite perfections. In Theology the object, far from being passive, by the act of creation first posits the subject over against itself, and then as the living God proceeds to impart to this subject that to which of itself it would have no access.
"For 'the things of God none knoweth, save the Spirit of God.' Strictly speaking, therefore, we should say that not God in and for Himself, but God in so far as He has revealed Himself, is the object of Theology." -- Geerhardus Vos, Inaugural Address