47. However, the center of this preparation must be a reflection in the faith on the sacrament of Marriage through the Word of God and the guidance of the Magisterium. The engaged should be made aware that to become "una caro" (Matthew 19:6) in Christ, through the Spirit in Christian marriage, means imprinting a new form of baptismal life on their existence. Through the sacrament, their love will become a concrete expression of Christ's love for his Church (cf. LG 11). In the light of the sacramentality, the married acts themselves, responsible procreation, educational activity, the communion of life, and the apostolic and missionary spirit connected with the life of Christian spouses are to be considered valid moments of Christian experience. Although still not in a sacramental way, Christ sustains and accompanies the journey of grace and growth of the engaged toward the participation in his mystery of union with the Church.