John 1:1 — "The Word Was God"

Reformed theology reads John 1:1 as scriptural foundation for Trinitarian doctrine. The passage declares that the Logos was both pros ton theon ('toward God') and that 'the Word was God' (theos en ho logos)—a statement of identity, not mere proximity. This affirmation integrates into the systematic framework of Reformed theology as articulated in the Westminster Confession of Faith and Heidelberg Catechism.

The Reformed interpretation employs classical theological precision: the Word's deity and distinction from the Father are affirmed simultaneously. Calvin and later Reformed theologians recognized that John's prologue provides philosophical clarity about Christ's nature and the Trinity, grounded in Scripture itself. The creation statement ('through him all things were made') reinforces Christ's divine agency in the economy of redemption and sustenance of all creation.