Before anything existed, Father and Son decided in the unity of the Spirit to share their own life with us. They wanted to create a new family unit, thereby enlarging the scope of their own familial relations. This is the deep background of the Triune drama unfolding before us in the Jesus’ story.
The Son’s lowly appearance in history wasn’t a surprise. Nor was it a Plan B following Israel’s failure. The Son came as Jesus because of a joint plan conceived in eternity between the Father and Son in the Spirit. In love, the Father decided to send his Son and in love the Son consented to being sent. The Son who always existed in the “form of God” wanted to serve his Father in the “form of a servant” among us. And so the Son’s identity as lowly servant-son among us is identical with his identity in eternity. For the Son’s way of being God is to be the one sent as lowly servant. And to be sent as the dearly loved Son who does all things joyfully in response to his Father’s love.
Hence it should come as no surprise that the Son’s mission on earth is “to do the will of him who sent me and to accomplish his work” (John 4.34; cf. John 5:30; 6:38). This is who he always wants to be in response to his Father’s love for our sake. And let us remember that this mission is what Father and Son decided on together because they want a large family of son’s and daughters in union with the Son.