St Augustine of Hippo was a theologian and philosopher in the early Church. He is viewed as one of the most important Church Fathers in Western Christianity. Augustine wrote De Trinitate to try and correct the heretical teachings on the Trinity that were arising at the time.
He sought to define the Trinity and ensure that the three Persons were understood and given equality with regards to greatness. He stated that two parts of the Trinity are equal in power to the third part, eg:
the greatness of the Father + the greatness of the Holy Spirit = the greatness of the Son
No one part is greater than another or the sum of the other two. They are not the same nor are they separate, in fact they share the same nature.
Augustine used the idea and notion of love to explain the Trinity and its three parts -
he that loves, and that which is loved, and love. Love has three parts:
...the Trinity does not work indivisibly, but the Father does some things, the Son other things, and the Holy Spirit yet others: or else, if they do some things together, some severally, then the Trinity is not indivisible.De Trinitate 8:10
Explain the Catholic Church’s teaching on the Holy Trinity.
The Catholic Church teaches that the Trinity is three Persons in one, namely God the Father, God the Son and God the Holy Spirit. Each is distinct from one another, but all are God and share the same nature. God the Father is the creator and sustainer of all. He alone is responsible for creation and all humanity. Without God, nothing would have come into existence. God the Father is also seen as just that - a loving father who is all loving and is always waiting for us to return to him. God the Son is Jesus Christ, who is God incarnate. He is God made flesh on Earth and is the one who came to offer us salvation. God the Holy Spirit is the power of God at work on Earth. Through the power of the Holy Spirit, people get to know God and become closer to him.