Committed to the task of educating their children for love, Christian parents first of all can take awareness of their married love as a reference point. Marriage is not, then, the effect of chance or the product of evolution of unconscious natural forces; it is the wise institution of the Creator to realize in mankind his design of love. By means of the reciprocal personal gift of self, proper and exclusive to them, husband and wife tend towards the communion of their beings in view of mutual personal perfection, to collaborate with God in the generation and education of new lives. Christian marriage is a sacrament whereby sexuality is integrated into a path to holiness, through a bond reinforced by the indissoluble unity of the sacrament: "The gift of the sacrament is at the same time a vocation and commandment for the Christian spouses, that they may remain faithful to each other forever, beyond every trial and difficulty, in generous obedience to the holy will of the Lord: 'What therefore God has joined together, let not man put asunder'." (Pontifical Council for the Family: The Truth and Meaning of Human Sexuality, 1995).