 Calvin defined a sacrament as an earthly sign associated with a promise from God . He accepted only two sacraments as valid under the new covenant : baptism and the Lord 's Supper ( in opposition to the Catholic acceptance of seven sacraments ) . He completely rejected the Catholic doctrine of transubstantiation and the treatment of the Supper as a sacrifice . He also could not accept the Lutheran doctrine of sacramental union in which Christ was " in , with and under " the elements . His own view was close to Zwingli 's symbolic view , but it was not identical . Rather than holding a purely symbolic view , Calvin noted that with the participation of the Holy Spirit , faith was nourished and strengthened by the sacrament . In his words , the eucharistic rite was " a secret too sublime for my mind to understand or words to express . I experience it rather than understand it . " 
