The stricter school of Rabbi Shammai allowed divorced only for adultery. Christian marriage is not only a human union. It is also a sacramental union formed by God, as beautiful, intimate and wonderful as Christ's union with the Church. Jesus was on his last journey to Jerusalem to be crucified when he taught that the marriage covenant is an exclusive, permanent, life-long commitment. The indissolubility of marriage is a hard saying but cannot compare to the suffering Jesus endured for our sakes.
Christian discipleship is often costly, a sharing in the way of the cross.
Couples whose marriage involves suffering, inadequacy, and flaws are not failures they are partners in a fallen world who share in the sufferings of Christ, weathering storms that few escape. They are learning to love and be happy without being perfect. Still, some marriages are invalid from the beginning. The conditions and consent needed for a valid sacramental marriage go far beyond what is needed for a civil marriage. If the intention to form a life long commitment, with complete fidelity, and openness to children, is lacking, or if one partner does not have enough maturity to form a partnership of the whole of life, their marriage is invalid.