The Church’s teaching on marriage and on the complementarity of the sexes reiterates a truth that is evident to right reason and recognized as such by all the major cultures of the world. Marriage is not just any relationship between human beings. It was established by the Creator with its own nature, essential properties and purpose. No ideology can erase from the human spirit the certainty that marriage exists solely between a man and a woman, who by mutual personal gift, proper and exclusive to themselves, tend toward the communion of their persons. In this way, they mutually perfect each other, in order to cooperate with God in the procreation and upbringing of new human lives.