I once had a young friend and student ask me regarding a course I teach called “Trinity and Christian Life” whether there’s anything we could say about Trinity for an entire semester. I appreciated the truthful question, if not because the unfortunate other mode this question often takes is framed less benignly as why one would spend an entire semester on such a useless topic! It’s an unfortunately valid question not because it should be, but because this seemingly strange doctrine has come to lose its spiritual meaning. It’s to that meaning that, among its other positive attributes, the doctrine of Trinity must be returned.

To do that, we have to first see that the doctrine of the Trinity does not stem from a few people sitting around talking after one too many bourbons proclaiming “I have an idea!” It has its historical roots. It emerges for two sets of interrelated reasons: because of the seemingly strange scriptural statements concerning the main three characters of Trinity as Fr., Son, and Holy Ghost; and for philosophical reasons in that it became a clarification for talking about Christ as divine. This latter is the more interesting.

At a very early stage in Christian liturgy, Christ became seen as not merely a prophet among other prophets, but as a definitive Word through whom God had saved both God’s people, Israel, and even the entire world. Christ was the act of salvation, and this point cannot be lost. The logic of salvation and creation go hand-in-hand, the one implying the other. As God created all out of nothing, so too in salvation is God preventing creation from falling back into the nothing from whence God drew it. And as God alone can create out of nothing, so, too, can God alone save from nothing.

So far as early Christians saw it, this is precisely found in the work of Christ. If Jesus isn’t welcoming a sinner back into the community, he’s healing the blind and lame, restoring their natural capacities back to the way they were always supposed to have been. Or else he’s raising the dead and quelling the chaos of the storm. These acts aren’t merely proofs for early Christians that Christ is divine; they are the very acts of salvation God brings through Christ to the world.

To briefly complete this logic, Christ brought salvation with him; the Holy Ghost continues this salvation. Thus, based on the logic of salvation alone, both Christ and the Holy Spirit must be divine since only the divine can save, which is what early Christians argued against a daunting and powerful heresies called Aryanism and Eunomianism. And the list of clarifications, including how to formulate the concept of Trinity--one essence, and three relations in the west--emerged, found its sway, and became doctrine.

While that’s entirely too short of an explanation, we must keep our eyes on the main issue: why should we even talk of Trinity? Well, you might say that Trinity is the very grammar of salvation for the Christian so that to ignore it is to miss out on the full nature of salvation. But more importantly, a beautiful spirituality emerges from Trinity, one entirely consistent with the whole of Christian spirituality.

As with all things today, spirituality is individualized, made about me, who I am, and what I want. But from the standpoint of a Trinitarian spirituality, that doesn’t work. The reason pertains to the idea that, at least as the Trinity is framed above, as one essence and three relations, we incorporate relationship and relationality into our spirituality. For the Triune God, who is an eternal giving and receiving of care and life, ought to be reflected in its creation. No longer, then, can spirituality merely mean praying by oneself for a sense of meaning, however valid such a mode of spirituality can be. It must take its fullness in our praying with one another, indeed, within the church service, but just as importantly, through a constant care for others outside the service that directly reflects the Trinity’s constant capacity to find oneself in another.

It is for this reason, among all other doctrinal reasons, that Trinity matters: through it we see that we are and have always been called beyond ourselves, receiving ourselves not from what we make ourselves into but from the other whom we love. We only become ourselves by receiving ourselves, which is a lesson the modern world could stand to hear out.

Dr. Eric Hall is an Associate Professor of Theology and Philosophy at Carroll College and author of "The Homebrewed Christianity Guide to God."