Our culture has seriously misinterpreted sexuality by separating it from it from the person. In this context the Church knows that her mission is to build up human life on the basis of an integral vision of the person. Human love is based upon the nature of the human person. Sexual love within marriage does not depend merely upon subjective intentions, but upon objective standards.
If we have an integral vision of man and his vocation we can see that there is an inseparable connection between the two meanings of married love: the procreative and unitive meanings are intrinsically linked.
Contraception separates these two meanings, acts as arbiter of the divine plan and degrades human sexuality. Contraception changes the innate language of total reciprocal self-giving by contradicting it. Thus, human sexuality is closed to life and the inner truth of married love is made false.
On the other hand, natural methods of fertlity management, which have recourse to the periods of infertility, respect the inseparable bond between the procreative and unitive meanings of sexual love and act as ministers of God's plan leading the spouses to benefit from their sexuality (becoming more human)!
Indeed, such is the difference between contraception and natural fertility management at both the moral and anthropological level, that they actually flow from two irreconcilable visions of the human person. Living natural fertility management leads spouses to experience the inner soul of sexuality through the tenderness, affection and dialogue by which it is embraced. Person and nature in the unity of body and soul are reverenced, not broken apart.