On the festival of the Holy Trinity, we celebrate the mystery that the One eternal, undivided God exists in three divine Persons: the Father, the Son, and the Holy Spirit. These three Persons are each fully and eternally God, but there is still only one God. This is not a puzzle to be solved, but a mystery beyond human comprehension. Although we cannot fully understand it, we can rejoice that the doctrine of the Trinity reveals the depth and glory of God’s never-ending love.