Crash course in Trinitarian thinking

Today is Trinity Sunday in the Western Church's calendar. Interesting, other than Christ the King Sunday, a 20th century development, Trinity is the only Sunday on the calendar which commemorates a concept rather than an event.

On Trinity Sunday we remember that while God is one there is a mysterious three-ness about him -- three persons (persona -- not to be confused with the modern concept of more individualized personalities) -- who are so in communion and so united that they are, always have been, and always will be fully one. The technical word for the intercommunion within the Holy Trinity is perichoresis (thanks to St Gregory of Nyssa) -- the "dance" that the members of the Trinity do together in perfect harmony -- and which they have through the incarnation of Christ Jesus invited people to join.

Certainly we are confounded by the notion of Trinity -- but that's nothing compared to the mystery of being invited to become participants in the perichoresis of the Trinity -- that which occurs when we are united with Christ and experience the new life "in Christ" (e.g. John 14:20; 15). As we are in him we have entry into the communal life of the Trinity. When we dance with him we are dancing with the fullness of the Trinity.