Reformed theology interprets Isaiah 7:14 as messianic prophecy fulfilled in Jesus's virgin birth. The Hebrew almah, while sometimes denoting a young woman, is understood in its prophetic and theological context as pointing to virginity and a miraculous conception. Calvin and Reformed commentators integrated this prophecy into the broader systematic understanding of Christology and redemptive history.

The Westminster Confession of Faith and Heidelberg Catechism affirm Christ's virgin birth as part of the doctrine of the Incarnation. The virgin birth testifies to Christ's unique divine nature and humanity, foundational to his mediatorial work. Reformed theology understands this prophecy within the economy of redemption: God appointed a time and manner for the Word to assume human flesh.