I’m talking about cross-Christian conversions, from Protestant to Catholicism or Orthodoxy, or the opposite. In calling such conversions “tragic,” I’m not suggesting that they always have adverse consequences for the convert. They may do, but not necessarily. In my view, someone who converts from drifting, unanchored liberal Protestantism to join a vibrant Catholic parish has made a step in the right direction, a step in the direction of Jesus.

What I have in mind is the logic behind some conversions, namely, the quest of the true church. Protestants who get some taste for catholicity and unity, who begin actually to believe the Nicene Creed, naturally find the contemporary state of Protestantism agonizing (as I do). They begin looking for a church that has preserved its unity, that has preserved the original form of church, and they often arrive at Catholicism or Orthodoxy.

Apart from all the detailed historical arguments, this quest makes an assumption about the nature of time, an assumption that I have labeled “tragic.” It’s the assumption that the old is always purer and better, and that if we want to regain life and health we need to go back to the beginning.

That, I think, is a thoroughly un-Christian assumption. Truth is not just the Father; the Son - the supplement, the second, the one begotten - identifies Himself as Truth, and then comes a third, the Spirit, also Truth, the Spirit of Truth. Truth is not just in the Father; the fullness of Truth is not at the origin, but in the fullness of the divine life, which includes a double supplement to the origin.

History is patterned in the same way. Eden is not the golden time to which we return; it is the infancy from which we begin and grow up. The golden age is ahead, in the Edenic Jerusalem.

And the church’s history is patterned in the same way too. It’s disorienting to think that we have to press ahead rather than try to discover or recover the safety of an achieved ecclesia , disorienting because we can’t know or predict the future. But it’s the only assumption Trinitarians can consistently make: The ecclesial peace we seek is not behind us, but in front. We get there by following the pillar of fire that leads us to a land we do not know.