Pope John Paul II in Familiaris consortio provided the Church and the world with an overview of why Humanae vitae was prophetic teaching of the Church of Christ. The late Holy Father began by underscoring the unity of the bishops with the Supreme Pontiff:
Thus, in continuity with the living tradition of the ecclesial community throughout history, the recent Second Vatican Council and the magisterium of my predecessor Paul VI, expressed above all in the Encyclical Humanae vitae, have handed on to our times a truly prophetic proclamation, which reaffirms and reproposes with clarity the Church's teaching and norm, always old yet always new, regarding marriage and regarding the transmission of human life.
For this reason the Synod Fathers made the following declaration at their last assembly: "This Sacred Synod, gathered together with the Successor of Peter in the unity of faith, firmly holds what has been set forth in the Second Vatican Council (cf. Gaudium et spes, 50) and afterwards in the Encyclical Humanae vitae, particularly that love between husband and wife must be fully human, exclusive and open to new life (Humanae vitae, 11; cf. 9, 12)."
Christians can see that the relationship between man and woman is fundamental. The relationship is always unitive, and always open to the possibility of life, according to nature's design. Pope Paul VI, did not teach something new in 1968, but merely reaffirmed what the Church has always taught. We are seeing today, the bitter fruits of not listening to the Pope. Women degraded, families destroyed, men brutalized. Abortion has never been so rampant, with women on the Pill having an average of THREE chemical abortions per annum. Truly we live in a "culture" of death.