In one sense, however, both preachers were right. To address the topic of the Blessed Trinity, one can literally spend hours speaking about the sublime simplicity and the profound complexity of God only to discover the truth: we are confronted with a mystery that must be believed.

Trinity Sunday presents us with a magnificent insight into the Being of God. God is One and God is Three. I don’t think that anyone can outdo the genius of St. Patrick in using the shamrock as one of the best teaching devices on the subject. Simple and readily available to his people, Patrick showed the one shamrock with the three leaves as the proof that such a thing could exist. The rest, of course, depends upon faith.

The words of Jesus in the 14th chapter of John’s Gospel, certainly give us insight into Jesus’ revelation of the unity of the Father and the Son and their indwelling with the disciples of Jesus.

Those same disciples will profess belief in Christ to the world through the Spirit of Truth who will also dwell within them. This beautiful theme of “indwelling” is a major theme of John’s Gospel. As you read and pray through the Gospel, reflect deeply on how often Jesus refers to his unity with Father and that unity being the sign of the community of his disciples. The Spirit testifies to this unity and guarantees it, as the Spirit of Truth.

Another great image for depicting the Trinity comes to us from the ancient symbol of the triangle within a circle. For an object lesson in what I’m saying here, you could draw such a diagram. Be sure to have the triangle intersect at three points within the circle and be sure that all three lines of the triangle are equal (that’s essential in understanding Three Equal Persons, One God).

At the points of intersection write: “Father,” “Son,” and “Holy Spirit.” On each of the lines of the triangle write: “Is not.” On the outer drawing of the circle write: “Is God.” When you’re finished, the lines of the triangle will tell you that the Father “is not” the Son; the Son “is not” the Holy Spirit; and the Holy Spirit “is not” the Father. The circle will tell you: The Father is God; the Son is God, and the Holy Spirit is God.

This simple (yes, it is) diagram basically illustrates the teaching of St. Athanasius who defended the divinity of Jesus and his existence as the Son of God. The result was the Council of Nicea (325 AD) and the Nicene Creed that we pray every Sunday at the Mass. There, of course, is our perfect doctrine and profession of the Trinity: One God: the Father, and the Son, and the Holy Spirit. Three Persons, equal in majesty and perfect in unity. How awesome is our God!