Our God is three persons mutually indwelling one another in other-centred love. Within this communion of three persons, there is one purpose born out of the self-giving love of the three. And the three persons move indivisibly as One to achieve this single purpose.
What is the One purpose shared by the three? We can state the purpose in a single word-inclusion. The three want to extend the communion of love to include us. They are fully satisfied within the Triune communion. They do not need to move beyond themselves in order to gain fullness. Nevertheless, they do not want to live within themselves and for themselves. They rather want to open up the Triune circle to include others.
Together the three decided that the Father’s Son would become human so that in union with him we might be included in the Triune Communion of love. And all things were created through Christ and for Christ so that in Christ we humans might share in the Son’s love relationship with the Father in the Spirit. Yes, the One purpose arising out of the Triune communion, before time, is our adoption into the Son’s relationship with the Father so that in the Spirit we might participate in the Triune Communion of love.
If we want to understand who we are and why we are here, then we must begin with the One purpose of the Three. This single purpose holds the answer to the “why” of creation, the “why” of your life and mine.