Unfaithfulness to him by the Israelites was adultery. John the Baptist, in the New Testament, carries over the same imagery. The union of man and wife in Christian marriage is, in fact, a graced participation in the very union of Christ with his Church. Baptized persons in the exchange of their marriage vows, administer the sacramental contract to each other. An unbaptized person, in the exchange of the marriage vows, confers a sacred contract, but the union is not a Sacrament.
All marriages are sacred and holy unions, but among the baptized, they are also Sacraments.
Sacraments are signs and gestures of the Lord's loving work of salvation which continues through history. Though the work of God is perhaps more understandable in Baptism which inaugurates a new life, still in the vow of the bride and groom not only do they give each other themselves but also an increase in the very life of God. As we have seen, each Sacrament confers or increases sanctifying grace, the life of God. The sacramental union of husband and wife in marriage becomes a channel of divine grace. Those, therefore, in the sacramental bond of marriage are qualified to receive God's assistance throughout the existence of their marriage contract for the fulfillment of the responsibilities of this vocation.