20 The Law in its progress still follows the sequence of the Gospel mystery, of which it is the shadow; its types are a faithful anticipation of the truths taught by the Apostles. In the vision of his dream the blessed Jacob saw God; this was the revelation of a mystery, not a bodily manifestation. For there was shown to him the descent of angels by the ladder, and their ascent to heaven, and God resting above the ladder; and the vision, as it was interpreted, foretold that his dream should some day become a revealed truth.
The Patriarch's words, The house of God and the gate of heaven, show us the scene of His vision; and then, after a long account of what he did, the narrative proceeds thus: And God said unto Jacob, Arise, and go up to the place Bethel, and dwell there: and make there a Sacrifice unto God, that appeared unto you when you fled from the face of Esau. If the faith of the Gospel has access through God the Son to God the Father, and if it is only through God that God can be apprehended, then show us in what sense This is not true God, Who demands reverence for God, Who rests above the heavenly ladder.
What difference of nature separates the Two, when Both bear the one name which indicates the one nature? It is God Who was seen; it is also God Who speaks about God Who was seen. God cannot be apprehended except through God; even as also God accepts no worship from us except through God. We could not understand that the One must be reverenced, unless the Other had taught us reverence for Him; we could not have known that the One is God, unless we had known the Godhead of the Other. The revelation of mysteries holds its appointed course; it is by God that we are initiated into the worship of God. And when one name, which tells of one nature, combines the Father with the Son, how can the Son so fall beneath Himself as to be other than true God?
Source: On the Trinity (New Advent)