In Reformed theology, the Lord's Supper or Eucharist is a sacrament that spiritually nourishes Christians and strengthens their union with Christ. The outward or physical action of the sacrament is eating bread and drinking wine. Reformed confessions, which are official statements of the beliefs of Reformed churches, teach that Christ's body and blood are really present in the sacrament and that believers receive, in the words of the Belgic Confession, "the proper and natural body and the proper blood of Christ." The primary difference between the Reformed doctrine and that of Catholic and Lutheran Christians is that for the Reformed, this presence is believed to be communicated in a spiritual manner by faith rather than by oral consumption. The Reformed doctrine of real presence is called "pneumatic presence" (from pneuma, a Greek word for "spirit"; alternatively called "spiritual real presence" or "mystical real presence").
Early Reformed theologians such as John Calvin and Heinrich Bullinger taught that Christ's person, including his body and blood, are presented to Christians who partake of it in faith. This view of the real spiritual presence was formally formulated by both Calvin and Bullinger in the Consensus Tigurinus. The historic Reformed confessions of faith, including the Second Helvetic Confession (Continental Reformed), Westminster Confession (Presbyterian), Thirty-Nine Articles (Anglican), and Savoy Declaration (Congregationalist), hold to the doctrine of real spiritual presence.