The Holy Trinity, One God

The central Christian dogma that the one God exists in three Persons and one substance, Father, Son, and Holy Spirit. The God who reveals Himself to mankind is one God equally in three distinct modes of existence, yet remains one through all eternity.
         
                                                                                                                             The Concise Oxford Dictionary of the Christian Church 

In the divine nature, the unity of the Godhead, there are three Persons, the Father, the Son, and the Holy Spirit. This is the Holy Trinity.

The three Persons are entirely distinct from one another in their relations of origin: the Father generates; the Son is begotten of the Father by an eternal generation; the Holy Spirit proceeds by an eternal procession from the Father and the Son.

But all are co-eternal and co-equal. All are uncreated and all-powerful. All have always existed. All are the one divine nature, one God.

One God in three Persons, the consubstantial Trinity, each Person being entirely God.

The Father is entirely in the Son and entirely in the Holy Spirit. The Son is entirely in the Father and entirely in the Holy Spirit. The Holy Spirit is entirely in the Father and entirely in the Son.

Even as the divine Persons are one in their nature, so are they one in their operation. But within the common action, each of the Persons shows forth what is proper and unique to him in the Trinity.

The First Person of the Trinity, God the Father, the maker of all things visible and invisible, the fount of life, light and holiness. The Omnipotent Lord. The Father is Truth and Love. Creation is especially to be attributed to God the Father, but it remains that Father, Son and Holy Spirit are together the indivisible principle of creation. The creative action of Son and Holy Spirit is inseparably one with that of the Father.

The Second Person of the Trinity, God the Son, the Logos or “Creative Word” through whom all things were made, Holy Wisdom, the Redeemer, the Image of the Father, the one who reveals God’s nature to us. The Son is the eternal focus of the Father’s love, and mediator of the Father’s love in creation and redemption.

The Third Person of the Trinity, God the Holy Spirit, the Sanctifier, the Life-giver, the Breath of God, Goodness, God at work in the universe and in our souls. The Holy Spirit, called the ‘Spirit of Glory’ and the ‘Spirit of Christ’, is the very Life of the worlds. We approach the Father, through Christ, in the power of the Holy Spirit.

God is the source and goal of all evolutionary progress.