It is the conviction of nearly all Christians that theology is “Christocentric” – all talk about God revealed in the Bible revolves around the person and work of Jesus Christ. Moreover, all theology is Trinitarian. (Obviously…and yet not so obviously – it took someone like Karl Barth before the church really came to terms with this in the 20th century.) And on top of that, as nearly all theologians are now recognizing, all theology is eschatological, that is, all theology is forward-looking, or to use George Ladd’s famous phrase, there is an “already but not yet” aspect to basically every Christian doctrine (e.g. the kingdom has come, and yet it is still future; we have been saved, we are being saved, and we will be saved).
Wolfhart Pannenberg adds another unifying factor to theology: the Holy Spirit. Central to Pannenberg’s view is that eschatology is really an expression of the Spirit’s work: according to Veli-Matti Kärkkäinen, “[Pannenberg] has shown us more clearly than anybody else the integral connection of pneumatology to the rest of the systematic topics, and thus the critical role of the Spirit of God in all God’s dealings with us from creation to sustenance to life to salvation to Christian community to the consummation of creation at the eschaton.”
This is very exciting on a personal level – we are being saved by the increasingly evident work of the Spirit. He has made us a part of the inaugurated reign of God (John 3:6-8). He has made us experience a foretaste of the resurrection even as we await the resurrection of our bodies at Christ’s return (Romans 8:10-11). He is producing in us spiritual fruit like love and joy that will one day be characteristic of our perfected, resurrection life (Galatians 5:22-23). He is conforming us into the image of Jesus (2 Corinthians 3:5-4:6). What is especially exciting is that the salvation he works within us will overflow and bring about the complete restoration of creation (Romans 8:20-23).
 Veli-Matti Kärkkäinen, “The Working of the Spirit of God in Creation and the People of God: The Pneumatology of Wolfhart Panneberg,” in Pneuma 26 (2004): 31.