Biblical theological reflection is not timeless speculation about the nature of the good, but the life and death struggle of the concrete historical communities of the Christian church who are trying to be faithful in their own particular historical contexts to the imperatives of the gospel in mission to the world. But the heart of the enterprise is christological; its content is Jesus Christ and not its own self-understanding or identity. Therefore the aim of the enterprise involves the classic movement of faith seeking knowledge, of those who confess Christ struggling to understand the nature and will of the One who has already been revealed as Lord.Childs here counters the claim that the theological study of Scripture is out of touch with the here and now. Rather, theological reflection actually transforms the one who engages in it. The interpreter is "grasped" by the one he attempts to know through his study.
The true expositor of the Christian scriptures is the one who awaits in anticipation toward becoming the interpreted rather than the interpreter. The very divine reality which the interpreter strives to grasp, is the very One who grasps the interpreter. The Christian doctrine of the role of the Holy Spirit is not a hermeneutical principle, but the divine reality itself who makes understanding of God possible.
Brevard Childs, Biblical Theology: A Proposal, 68-69.
Theology deals with life and death because it sustains those who are in a life and death struggle to know God in Christ and make him known.