The Father chose his unique Son to go the way of lowly service for us. And the Son freely chose to go that way as the Lord who serves. Father and Son made this decision together in the Spirit
Jesus did not go this way of lowly self-giving service alone. He was always in the Father and the Father in him. Jesus, therefore, went the way of lowly Servant-Son in union with his Father in the Spirit. The Father sends his Son into the world to serve in lowliness and he is in his Son as he serves. The Spirit rests on the Son as he serves his Father and us so that all he does is in the Spirit. So in Jesus, the lowly servant, the Triune One is among us making his eternal decision happen in history. His decision to be God with us and for us; and for us to be with him.
But what kind of happening is it? Might it not have happened? For sure, all that happened in Jesus within history is rooted in the divine decision which is divinely fulfilled in Jesus. He comes among us rescuing us from the power of sin and death. He dies to end the reign of sin and death over us and we die to that reign with him. He rises as the new man in the new creation and we rise with him to newness of life. He is himself the dramatic saving happening in history making actual God’s communal decision. And now by the Spirit the same Jesus happens in us calling us to faith and sure expectation for the future.