Glenn has contributed to Credo in many ways in the past. So it's really great to finally have him on the Credo podcast to discuss a doctrine as important as a Trinity. Glenn, thank you for joining us.

Thanks so much for having me on.

Glenn, I think for a lot of our listeners out there, maybe they're past pastors and local churches, maybe they're students studying in the ministry. Maybe they're other scholars who have started to dip into the deep well of Trinitarian research. But regardless, I think many of them know just instinctively that they should be affirming a nice-seeing doctrine of the Trinity. And with that, we could use a word like consubstantiality. They understand that whatever person of the Trinity we are talking about, whether it's the father, the son, or the Holy Spirit, they understand that they are consubstantial with one another. But at the same time, there's been a lot of confusion over the last several decades as to how to distinguish the persons. What are these personal properties that sometimes are mentioned in the great tradition? How do we distinguish the persons and in a way that still preserves their divine simplicity? And this is one of the reasons why, Glenn, I'm so thrilled to have you on because you have given this a lot of thought, not just historically, but even biblically. How is it that scripture? How is it that divine revelation itself brings us to an understanding of the Trinity that is precise, but it also brings us into the mystery of this infinite and holy Trinity. And one of the ways that you've done that is you bring us into contact, not just with the biblical witness, but the great tradition. And so the first question that I just want to throw at you, Glenn, is for, and I know this is going through the minds of many of our listeners, when we use a phrase like personal properties, or perhaps another word like processions, what did the great tradition mean by these phrases? And maybe the question behind the question is this, why was this language even introduced to begin with?

Those are great questions. So the idea of a procession and the idea of a personal property is really closely connected, but they're technically a bit distinct conceptually. When we speak of the Trinity, whenever we're looking at those things that are shared by Father, Son, and Holy Spirit, which is being omnipotent or omniscient or good, for example, it's traditional to say that we are speaking of the singular divine essence or being. However, when we are looking at something that is proper to only one of the persons, such as being the son or such as being begotten, traditionally Christians have said that the son is eternally begotten of the Father, then we're moving into territory of processions and personal properties. And these are concepts that Christians have used to try and explain how Father, Son, and Spirit are eternally different, basically rejecting modalism, the idea that there's a singular God who just kind of appears in history in different forms. One day as the Father, maybe the next day as the son, but traditionally, since well before the Council of Nicaea even, Christians have insisted that the distinctions are eternal. So the processions are the ways to think about those distinctions in relational terms. So the Father eternally begets the son. The concept of eternal generation or eternal beginning is a relational concept describing that eternal relationship between Father and Son. And then speaking of eternal spiration or eternal procession of the Holy Spirit clarifies the relationship between the Father and the Holy Spirit. And then of course, we have this big debate between Western and Eastern Christians over how the Holy Spirit and the Son relate. We can just table that for a moment. The personal properties, on the other hand, are properties that we would attribute to one of the divine persons based on these processions. So if we speak of eternal generation sort of as the relationship between Father and Son, then we can speak of the Son as being generated. And that would be a personal property. So it's a way to think about the uniqueness of the Son that focuses a bit more on the unique characteristics of the Son and a little bit less on the relationship. So it is still

implied.