The Lord’s Supper, a sacrament, is Christ’s very body and blood, “under the bread and wine,” given and shed for the forgiveness of sins (Matt. 26:26-28; Mk. 14:22-24; Lk. 22:19-20; 1 Cor. 10:16; 11:23-26). It is a “means of grace,” through which God gives “forgiveness of sins, life, and salvation.”
Though it is a gift, it can be take to one’s judgment (1 Cor. 11:27-29). Out of love for the Lord and His Word and concern and for those who partake of the Lord’s Supper, Lutheran’s practice close(d) communion, communing only with those who hold the same confession of faith, for the Lord’s Supper is also an expression of the unity in doctrine (faith) confessed at the altar.