We seem to consider mysteries in almost mathematical terms: they are problems so enigmatic, so contradictory that they cannot ever be solved. The Doctrine of the Holy Trinity does present us with a seeming contradiction. It tells us that three equals one, when we know that three doesn’t equal one. Yet, we have to believe it or forfeit the name of Christian, so we assent and we move on to the prayer at hand.
But mystery is not mathematics. It would be more helpful for us to think of mystery in terms of marriage, or indeed any deep human relationship. We cannot ever ‘figure out’ a spouse, but we can certainly grow in love, knowledge, and understanding of that person. The Trinity is the loving relationship we hope to know forever in heaven. If we are not growing in our love of that mystery, we are not growing any closer to heaven.
The word, ‘Trinity’, does not appear in the Scriptures. It is a theological term coined by Christians to describe the reality at the Heart of Divine Revelation. St. Matthew’s Gospel ends with Jesus’s command for the disciples to baptize, ‘in the name of the Father, and of the Son, and of the Holy Spirit’. St. Paul assumes this same mystery when he pronounces the benediction that we use in the Mass: ‘The grace of our Lord Jesus Christ, the love of God and the fellowship of the Holy Spirit’.