Wisdom on the purpose of theology from John Franke

…the purpose of theology is mission. Theology that is faithful to its subject engages in the life and the work of the church by articulating, assisting, promoting, and participating in the missional vocation of the church. Hence, theology that is properly attuned to its subject (God) and its focal point (the church) will be missional theology. The critical and constructive task of theology is pursued not simply to secure right belief or to correct false teaching but to assist in the promotion of the accomplishment of the mission of God. The commands to love God, be transformed, discipline our thoughts, and be ready to account for our hope are all connected to the calling and the participation of the church in the mission of God. This missional vocation should shape and orient all the beliefs and practices of the Christian community.

The Character of Theology, 166 (John R. Franke)

For more on “missional theology” see this short, introductory essay.