The primary responsibility for convincing people not to use unnatural methods of birth control falls on the bishops and their priests. The Nicene Creed is professed on 52 Sundays and a few other major feast days every year. That provides priests with 52+ occasions on which to preach the acceptance of Catholic teaching on love and sex, as well as every other matter. The same Holy Spirit who guided the bishops at Nicea guided the Tradition against contraceptive behaviors, guided the affirmation of Pius XI in Casti Connubii in 1930, guided the affirmation of Paul VI in 1968, and continues to guide the Church today. Theology and science can uphold and explain the teaching, but only the well founded belief in the Spirit-led Magisterium provides the certainty required for action.
John F. Kippley
Sex and the Marriage Covenant