So now you are asking, “So, what? This has all been a great intellectual exercise, but why does it matter? What real significance does the Trinity have for Christians now?” Great questions.
“It is not the doctrine of the Trinity which underlies the Christian faith, but the living God whom we encounter through Jesus Christ in the power of the Holy Spirit. The God who is the Trinity…The doctrine of the Trinity is to the Christian experience of God what grammar is to poetry. It establishes a doctrine, a framework, which allows us to make sense of something which far surpasses it. It is the skeleton supporting the flesh of Christian experience.” (Studies in Doctrine, Alister McGrath)
“The doctrine of the Trinity helps us make sense of the encounters Christians have had and continue to have with the living God.” (Christian Hofreiter)
The Trinity is extremely critical for the Christian life because if we are to love God, we need to know God. To know God, we need to grapple with the Trinity.
One implication to start with is reading Scripture. We should be watching for hints of God’s three-in-one nature. We should be looking at the life and ministry of Jesus as the one and only God-man. We should also be searching for proof of the Spirit’s part in the strategy of salvation and our lives as believers today. Furthermore, we should be looking to better understand the relationships of each member of the Trinity with each other and with ourselves. This even applies to how we view the Gospel. Normally the good news is presented with Christ and the cross at the center. Yet if we are to view the Gospel with the lens of the Trinity, including the Father, Son and Spirit unified in their effort to save us, “It’s a start – a start to a lifetime of loving God and learning more and more about Him – our glorious three-person Redeemer.” (Exploring Christian Theology, Nathan Holsteen, and Michael Svigel)
There is also implication with what we learn about ourselves. When we think of the pronouncement in Genesis that we are made in God’s image (Genesis 1:26-27), the Trinity gives it a new meaning. Up until now, I have only thought of reflecting the image of God the Father when I pondered this passage, but I now know we are supposed to reflect the image of the Son and Spirit as well. Not only are we supposed to think about how each member of the Trinity separately, but we are to think of how they interact with each other as a whole. As the members of the Trinity “each thinks, speaks, wills, loves, and relates to the others. Scripture shows that our own personhood in community finds its roots in our Creator: we think, speak, will, love, and relate to others.” (Exploring Christian Theology, Nathan Holsteen, and Michael Svigel) This means we are not only to consider how our actions affect ourselves but also others around us. We are to care for each other, love our significant others, and have genuine friendships and community. When we do these communal things, we are mirroring the communal camaraderie of the Godhead: The Father, the Son, and the Spirit.
Finally, we are to be self-giving in every way. In our daily lives, our relationships, and our ministry we need to be willing to lose our lives for Jesus’ sake. “For whoever wants to save their life will lose it, but whoever loses their life for me will save it.” (Luke 9:24) Jesus came and willingly died on the cross for our sake, and we must be willing to pick up our cross daily (Luke 9:23) and serve others the same way. Even in the life, death, and resurrection, the servanthood and fellowship of the Trinity were at work. The Father offered all matters to the Son. The Spirit glorified the Father and the Son. The Son glorified the Father. This self-giving and communal way of the Godhead is how we are to live also.