The Father is God, The son is God, and The Holy spirt is God and yet there are not three gods but one god.
The Catholic Church teaches that the fathomless mystery we call God has revealed himself to humankind as a trinity of Persons- the Father, the Son, and the Holy Spirit
Three Persons, One God
The mystery of the Trinity is the central doctrine of Catholic faith. Upon it are based all other teachings of the Church. In the New Testament there is frequent mention of the Father, The Son, and the Holy Spirit. A careful reading of these passages leads to one unmistakable conclusion: each person is presented as having qualities that can belong only to God, how can this be?(199-202)
The Church studied this mystery with great care and, after four centuries of clarification, decided to state the doctrine in this way: in the unity of the Godhead there are three Persons-The Father, the Son, and the Holy Spirit- truly distinct one from another(249-256)
Creator, Savoir, Sanctifier (257-260)