Father, I desire that they also, whom you have given me, may be with me where I am, to see my glory that you have given me because you loved me before the foundation of the world. – John 17:24
For by him (Christ) all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—all things were created through him and for him. 17 And he is before all things, and in him all things hold together. – Colossians 1:16-17
And,“You, Lord (the Son), laid the foundation of the earth in the beginning, and the heavens are the work of your hands…” – Hebrews 1:10
He is the radiance of the glory of God and the exact imprint of his nature, and he upholds the universe by the word of his power. – Hebrews 1:3
The Father loves the Son and has given all things into his hand. – John 3:35
For the Father loves the Son and shows him all that he himself is doing. – John 5:20
I will no longer talk much with you, for the ruler of this world is coming. He has no claim on me, 31 but I do as the Father has commanded me, so that the world may know that I love the Father. Rise, let us go from here. – John 14:30-31
As the Father has loved me, so have I loved you. Abide in my love. – John15:9
And when Jesus was baptized, immediately he went up from the water, and behold, the heavens were opened to him, and he saw the Spirit of God descending like a dove and coming to rest on him; 17 and behold, a voice from heaven said, “This is my beloved Son, with whom I am well pleased.” – Matthew 3:16-17
Not only that, but we rejoice in our sufferings, knowing that suffering produces endurance, 4 and endurance produces character, and character produces hope, 5 and hope does not put us to shame, because God’s love has been poured into our hearts through the Holy Spirit who has been given to us. – Romans 5:3-5
The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with you all. – 2 Corinthians 13:14
And because you are sons, God has sent the Spirit of his Son into our hearts, crying, “Abba! Father!” – Galatians 4:6
Without the Trinity, we would not have an eternal loving Father God.
The fact that God is one God in three persons, Father, Son and Holy Spirit is of far greater importance than is realized by many. The Trinity is not just a doctrine to simply acquiesce to or maybe to argue about. Without God’s existence as Trinity, much of what we know and love would not be possible. We would not know God as an eternal loving Father.
Before God got around to creating anything, there was an eternal love affair between the Father and the Son and the Spirit. Jesus made this clear in what is often referred to as the High Priestly prayer in John 17. He was asking for the Father to allow those whom the Father had given to the Son to be allowed to see his glory which the Father gave the Son because the Father loved the Son before the foundation of the world.
That same love is what drove Christ to the cross, and is the same love that Jesus has given to those who are his followers. That same love is poured into our hearts by the Holy Spirit.
This could not be with a singular, unitarian, non-trinitarian God. Before that kind of God created, there would be nothing to love except himself and that would be an inward looking love, a narcissistic love, that is nothing like the love of the God of the Bible. That unitarian God would be dependent on his creation to have an object of his love. He would not be complete in himself.
The love of the God of the Bible is always outward looking. It is always looking out for the benefit of the other. Before creation, the Father loved the Son and the Son loved the Father. The Spirit too entered into this reciprocal love and eventually poured that love into our hearts.
Without the Trinity, there would be no fellowship into which we could be drawn. God would not be personal; he would just be a creator/dictator. He would not be a loving Father. Instead, the love of God is poured into our hearts by the Holy Spirit, and we cry, “Abba,” Daddy. That is our eternal loving Father, the Father of the eternal Son and we become sons of God by faith in Jesus Christ and share in that eternal love affair.
I am really glad that God is Trinity.