Explain how a marriage, maybe lasting for several years and producing children, is considered a nullity if it ends in divorce.
Christian marriage is a sacrament that two Christians, a baptized woman and a baptized man, bestow on each other when they exchange their marriage vows. For the sacrament to be validly conferred, both the bride and groom must be capable of giving valid consent to fidelity, fruitfulness, and lifelong commitment. If conditions exist prior to the marriage that makes such consent impossible, then the consent was never exchanged and the sacrament never conferred. That the putative (i.e., “reputed”) marriage lasted several years and/or produced children are not factors in determining whether or not valid sacramental consent was conferred in the first place at the time the marriage took place. A decree of nullity recognizes that the sacrament was not conferred and that the couple is not bound by the marriage sacrament to the partner for the remainder of their lives.