Brevard Childs:

The early church’s theological reflection on the God of Israel did not turn on certain isolated Old Testament passages from which to find a warrant for a developing christology, but rather it turned on the issue of the nature of God’s presence within the life of Israel in all its historical specificity. The God of the covenant who had bound himself to a people in love, had revealed himself as both transcendent and immanent, seen and unseen, the God of the Patriarchs and of all nations. The church confessed to know a totally sovereign creator who yet chose to reveal himself in the forms of his creation, who entered time and space in order to redeem the world. In short, the church’s reflection on God found itself inexorably drawn into Trinitarian terminology in order to testify to God both as the revealed and revealer, the subject and object of self-manifestation.

— Biblical Theology of the Old and New Testaments: Theological Reflection on the Christian Bible, 369.