"When I say God, I mean Father, Son and Holy Spirit," St. Gregory the Theologian says, IIRC.
The Father is God. The Son is God. The Holy Spirit is God. Yet, they are not three Gods, but one God, not divided in essence, but separate in person. They are united in will and act together for the purpose of my salvation.
There are prayers to each Person of the Most Blessed Trinity, but these are not to the exclusion of the other two, and most end with a Trinitarian doxology.
Each Person, however, is fully God. The Holy Trinity is one in essence, but three in person. God is undivided and simple in essence, and yet He is known in three Persons. He is eternal, and yet He became temporal (in that He entered history, albeit remaining eternal). He is Spirit, and yet He took flesh.
Do you see all the paradoxes and how God does not fit into any kind of box we construct? What we know of God is from His revelation, not our limited human conception.