The first reading refers to God, and the actions of God in “the days of old, before your time.” It asks, “Did anything so great ever happen before?” So many in our days deny that there is a God and that everything just happened by chance in a big bang. They seem to be playing word games that are inconsistent with logic. Why? Because in order for there to be a big bang, something had to already exist in order to go ban! Second, in order for something that has been stable to go bang there had to be a cause for the bang. So even if the big bang happened, God had to have created whatever went bang. This would be an act of God the Father.
The second reading refers to the Spirit of God. We are “adopted” children of God. Though we must respond and act like children of God, or we fall back into fear. When the priest mixes the water with the wine in the chalice prior to the consecration he states, “by the mystery of this water and wine may we share in the divinity of Christ who humbled himself to share in our humanity.” That sharing in the divinity is brought about as we receive the Body and Blood of Christ.
In the Gospel Jesus specifically mentions the trinity in the baptismal formula we still use today, “baptizing them in the name of the Father,
and of the Son, and of the Holy Spirit” Thus from the beginning of the Church founded by Christ, there is a reference to the Trinity. One God, Three Persons. Anything one can say about the one they can say about the other, except they are the other.
Countenance of God 