The historical Congregational tradition affirmed the classical Reformed doctrine of God: one infinite, sovereign, omnipotent, omniscient, perfectly holy being, in three persons. The Savoy Declaration (Chapter II) reproduces the Westminster Confession's doctrine of God almost verbatim. The Cambridge Platform and the theology of New England Puritanism presupposed this classical theism as the framework for all Christian thought.

The United Church of Christ's Statement of Faith describes God as 'the Eternal Spirit, Father of our Lord Jesus Christ and our Father,' language intentionally open enough to accommodate different theological frameworks. The UCC has been a pioneer in feminist and liberation theology, with theologians such as Letty Russell and Carter Heyward developing models of God as relational, liberating presence rather than monarchical sovereign. The denomination officially employs inclusive and expansive language for God, and many UCC congregations use non-traditional names and images for God alongside or instead of traditional Trinitarian language.