This is the 3rd post in a recent series on the Trinity. Before you read this you should read the first two:
I’d like to finish with a brief consideration of why this all matters. To put it another way: “Why is it important to believe in the Trinity?”
At this point we have discussed (briefly) what the Trinity affirms and some of what it denies. Now comes the big question: so what? What impact, if any, does this doctrine have on being a Christian? What difference does the Trinity make for Christian belief, worship and practice? Does it inform what it means to be the Church, or more fundamentally, to be human? Let us be very clear, “what is at stake in the doctrine of the Trinity is God’s drastic commitment to us in Jesus Christ and the Spirit.” Therefore, the doctrine of the Trinity is really the central Christian doctrine “because it identifies God as the God of love who has opened his heart to the world on the cross,”(12). In both modalism and Arianism God is essentially distant and unknowable but this is a lie if the gospel is true. The gospel rejects both these portrayals of God, for God is with us. So, in a very important manner, the doctrine of the Trinity shapes how we understand and know God. God is not distant and “out there”. God is here in the flesh and blood of Christ Jesus and in his Spirit poured out among us.
In a similar way, the doctrine of the Trinity shapes our worship together as the people of God. The Trinity enables us to sustain our faith in a God who is both other than the world and radically immanent in the world, (13). To say that God is other than the world is not to say he is against the world. God is other than the world because he is the creator and is relational in his own inner-self. Yet, in the flesh and blood, life, death and resurrection of a poor first-century Palestinian Jew God is irrationally and undeniably present and poured out in our midst. The Trinity sustains our worship of this God.
Likewise, in our worship together, the Trinity shapes our reading of Scripture. Christians read Scripture “trinitarianly” because “we read it as members of the Church, the community that confesses faith in God as the Father, the Son, and the Holy Spirit; and reading Scripture that way, we discover that the God who is Trinity speaks to us,” (14). Certainly, Scripture does not explicitly “prove” the Trinity, but rather, alludes to it and those Scriptures that seem to be evident of the Trinity are sign-posts (to borrow an analogy from Tom Wright) that point us in the right direction. Christians read Scripture as shaped by and witnessing to the Trinity on every single page.
God is mysteriously one and three, other and immanent, and we know this because God has revealed himself as such. If the gospel is true, then God is Father, Son and Holy Spirit. The doctrine of the Trinity is perhaps most central to the life of the Christian and, therefore, the Church for it allows us to worship God as he really is.
12. Yeago, 163.
13. Mangina, lecture, Oct. 13.
14. Mangina, lecture, Oct. 13.