To respond with all clarity, one would need to read Humanae Vitae, by Paul VI, or the Catholic Catechism to understand the full answer to your questions, but, the simple answer is that contraception, like abortion, interfere’s with God’s plan for humanity’s continued preservation.
In the case of abortion, the parents are depriving God of his role in deciding the outcome of that pregnancy and of that being, their life.
In the case of contraception, the decision to create life is not one that is in the hands of just the couple involved, there is a third party, and that is God. Contraception tries to place man above God in the decision of when to create life. Also, the pill IS an abortificant as it prevents the fertilized egg from implanting in the uterine wall.
Real Catholics may, for extaordinary reasons, use natural family planning methods but they must always be receptive to life, whether it fits into their plans or not. We make this pledge to each other and to God in our wedding vows.
the planet is overcrowded....though the proportions are all wrong.
the 3rd world is breeding like rats and the intelligent westerners are not breeding...
there is no loss of humanity....but there is a loss of intelligent westerners....the solution??? beats me.