This was taken from a conversation I had on the importance of belief and doctrine with someone in r/Christianity.
How does one’s (your?) belief in the Trinity impact how you act towards God and your neighbor? In what way have you seen/do you imagine the belief in the tri-unity of God makes a real difference in a believer’s actions?
It absolutely does! First, St. Athanasius covered this ground in On the Incarnation. Second, I believe we all whether consciously or unconsciously can downplay the divinity of one or all three persons of the Trinity and in doing so, our Christian behaviors follow suit.
Central to this argument is the diminishing of Jesus Christ’s Godhood. Basically, the entire Christian faith hinges on it. If Jesus Christ is not God, then we have no salvation from sin and death because only the uncreated could redeem the created from this destruction. The plan from the beginning was for God to find a way to get back into total communion with His beloved creation. This ground is covered in Romans. As to how it causes us to act towards our neighbor -Christ is an icon of what we are to become. We are to become by grace what Christ was by nature, divine and in communion with God. We cannot become a god, but we are to become holy and inseparable from the one true God. If we can have this belief deep inside, you better believe it should cause us to be more humble, more compassionate, more broken and simply more like Christ.
Now, let’s talk about the Holy Spirit. Quite simply, if the Holy Spirit is not God then we are not in relationship with God. We are in relationship with a lesser intermediary. How does it affect how we act towards our neighbor? Same as with downplaying Christ’s Godhood, we diminish the ability for the divine presence in our lives to change us. And all three persons are the same thing. They are expressions of the indivisible God who wants to commune with us.
I see this as the very backbone for which we stand as followers of the living God, the Redeemer of all mankind and if it’s not important to you as a Christian, then it ought to be. Otherwise, you’ll have no more reason to be a Christian than you do any other preference in your life. Your faith will be reduced to something like preferring light meat over dark meat, or heavy metal over pop…it’ll have no real impact on your life.