The Encyclical letter Evangelium Vitae and the pastoral of life: for a new culture of life. The plan of God “written” in human body: biological aspects of procreation and human fertility. Natural Fertility Regulation as a lifestyle: a way of knowledge, love and responsibility between husband and wife. The Billings Ovulation Method: history, scientific fundaments, spreading in the world. Practical and educative aspects of Billings Ovulation Method for Natural Fertility Regulation in different situation of woman reproductive life. Infertility of the couple. Self-knowledge and love education in teenagers and young people. From Humanae Vitae to Amoris Laetitia: how can we help people to live a responsible procreation?