Church teaching on this subject is fundamentally tied to the commandment, “thou shall not kill”.
When God created mortal man, he also endowed us with the ability to procreate - a miraculous gift. Without this ability, Mankind, the pinnacle of God’s creation, would cease to exist without God’s continuing intervention, which would diminish the other great God-given gift of free will. When we interfere with God’s plan which ensures the very existence of His greatest creation, taken to the extreme, we subject Mankind to extinction - death of the species.
There are many who might rebuff this argument, using our own Church’s teaching (namely, that life begins at conception) to refute this argument. However, if one honestly looks to the consequencies, it is easier to see how this is a form of murder against Mankind.
Even if that is too much of a stretch for some philosophically, we can stop when we realize that we are interfering with God’s plan to ensure the survival of His greatest creation. It is this disobedience to God, also an offense against ourselves, that is essential to understanding the sinful nature of the use of contraception.
From popular culture, one of the most famous quotes from one of the last of the Jurassic Park movies alludes to the power of God’s will in propogating his Creation - life. The scientists made all of the dinosaurs genetically female, in an attempt to control the population of the restored species. They played God twice: (i) by restoring an extinct species and (ii) by genetically manipulating the result in an unnatural way. The result: the dinosaurs mutated and found a way to reproduce anyway. “Life finds a way!” Who are we to interfere with God’s plan?
BTW - while I believe the teachings of the Church, I am not an active pro-lifer, as it were, or anything like that. I have shared my understanding of the Church’s teachings that have come from my own study and my own life experience. I had once considered asking my wife to terminate a pregnancy. I was at a very vulnerable point in my life - jobless, and feeling very dejected and in utter despair. I did not feel I could take care of another child (we had two already). Something came over me after a few weeks of prayer and contemplation, and I soon saw very clearly the error of my thinking. The result of faith - my second son is sitting before me as I write. I realize my life would not be complete without him. Every day and every time I see him, I think of this experience and pray for those who may find themselves thinking similar thoughts in similar circumstances.
Not only does life find a way, but God does truly provide to those who have the faith to believe that he does and will. He did for me and my family - he will for you as well!
