The doctrine of the Trinity is not a puzzle for clever minds but a boundary line that keeps the church worshiping the true God rather than a god of our own speculation. Today Calvin tightens the distinction that must be held without tearing the unity: one divine essence fully present in Father, Son, and Spirit, distinguished not by parts of deity but by personal relations that do not divide God. He then turns to the recurring threat—old heresies wearing new clothes—exposing how theories that reduce the Son and Spirit to projections, fragments, or derived divinity destroy the gospel itself, because they turn Christ into something less than Yahweh. Calvin insists that Scripture’s divine titles, divine works, and divine worship given to Christ cannot be explained away without blasphemy, and therefore the Son is not a second-class God, not a borrowed ...