Selection from Fr. Thomas Joseph White, OP, The Light of Christ
(Washington, D.C.: CUA Press, 2017), 40-41.
Theology is a science in the sense that it has a proper object of study: the mystery of God made available in divine revelation. This science differs from all others because its first principles are derived from God revealing himself in Christ, something that transcends the limitations of natural human reason. The perspective that theology gives us in turn allows us to understand all things in light of the God of revelation, since God is the source of all that exists. If we take this approach, then we can see right away that there can be no genuine conflict between theology and the sound conclusions of any other "science" (whether philosophical or modern scientific), because these sciences deal with truths about what exists, about what God has created. Their true conclusions can be understood "from on high" in light of a higher or deeper knowledge concerning the mystery of God. But if all that exists comes from the Holy Trinity, then nothing we discover in reality can stand in contradiction to the divinely revealed truth about God. Seemingly irresolvable conflicts of faith and reason, when rightly understood, are always in the end pseudo-problems.
What kind of topics does theology treat, then? What problems does it solve? What questions could we possibly ask that it might profitably answer? The first answer is: it tells us who God is. Not as we could know God by our own natural powers, through philosophical speculation. On that level, we can come to know that God exists, but what God is in himself remains largely hidden from us, due to divine transcendence. Christian theology, however, considers who God is in himself, in his own inner life. The mystery of the Trinity is the primary mystery in Christianity, because it concerns who God is and the fact that God has willed to offer us knowledge of himself, or even participation in his own divine life by grace: "He has granted to us his precious and very great promises, that through these you may escape from the corruption that is in the world because of passion, and become partakers in the divine nature.”