“God is triune, and all reality is structured in terms of Him. A brief definition of the Trinity might be this: One God without division in a plurality of Persons, and three Persons without confusion in a unity of essence.
God is not 'basically' One, with the individual Persons being derived from the oneness; nor is God 'basically' Three, with the unity of the Persons being secondary. God is One, and God is Three. There are not three Gods; there is only one God. Yet each of the Persons is Himself God — and They are distinct, individual Persons. But there is only one God.

"To put it in more philosophical language, God’s unity (oneness) and diversity (threeness, individuality) are equally ultimate. God is 'basically' One and 'basically' Three at the same time. And the same goes for all of creation. Both unity and diversity are important – equally important. Neither aspect of reality has priority over the other.”