Sacramental union
In Protestant sacramental theology, sacramental union (Latin, unio sacramentalis; Luther's German, Sacramentliche Einigkeit;German, sakramentalische Vereinigung) is the relationship between the outward substance or "sign" of a sacrament (such as the physical washing of water in baptism and the physical elements of the Lord's supper) and the thing signified by the sacrament (such as regeneration and remission of sin in baptism and Christ in the Lord's supper). Lutherans believe the sign and thing signified to be locally united, so that Christ is bodily present at the Lord's supper. Reformed Christians believe the sign and thing signified to be inseparable, but to be united spiritually rather than locally and bodily.
Type of union
The sacramental union is distinguished from the other "unions" in theology like the "personal union" of the two natures in Jesus Christ, the "mystical union" of Christ and his Church, and the "natural union" in the human person of body and soul. It is seen as similar to the personal union in the analogue of the uniting of the two perfect natures in the person of Jesus Christ in which both natures remain distinct: the integrity of the bread and wine remain though united with the body and the blood of Christ.
