Athanasius here describes the orthodox and Catholic teaching on God as Trinity, three persons in one divine nature, a wholly creative and energizing reality. The Father, Son and Holy Spirit are an inseparable unity, always acting together.
It will not be out of place to consider the ancient tradition, teaching and faith of the Catholic Church, which was revealed by the Lord, proclaimed by the apostles and guarded by the fathers. For upon this faith the Church is built, and if anyone were to lapse from it, he would no longer be a Christian either in fact or in name.
