Let me first say that although I have always been Catholic, I once had a real problem with the Church’s teaching on artificial birth control. I thought it was old, celebate men in Rome who didn’t have any understanding of what sex was about, so why should they tell me about my sex life?
However, something compelled me to find out WHY the Church teaches what it does, and slowly I opened my heart to the teaching of the Church.
Now, there are practical reasons to avoid artificial birth control as well as theological reasons. I will be happy to go into the practical reasons, but they are not the reasons the Church teaches against it, so I"ll stick to theological reasons.
There are lots of great resources on this, so I"ll try to keep it short.
Basically, when you give your self in marriage, you are giving yourself to your spouse in a way parallel to the way Christ gave Himself to the Church. (Why else would Christ be called the Bridegroom and we the Bride?) Christ’s love is ALWAYS free, total, faithful and fruitful (life-giving). When you give yourself to another in marriage, your vows are to love that person freely, totally, faithfully and fruitfully. When using contraception, you are not giving yourself to your spouse totally. You are keeping your fertility to yourself. Also, you are not giving yourself fruitfully, either. Christ’s love is always life-giving, not just sometimes. The marriage act is also life-giving and its our job to make sure we are not the ones who render it sterile - or break the life-giving component of the act.
In addition, contrary to popular belief, the Church is not down on sex. In fact, the reason its against artificial birth control (ABC) is because its so for sex. When we have sex, God is allowing us to participate in the most holy thing I can imagine - the forming of a new human being made in His image. When we use ABC, we are telling God that we don’t want to be a part of that. We are telling Him we know more than He knows and we are shutting him out of the one thing that separates our relationship with our spouse from our relationship with everyone else. If we want God to be a part of our daily lives, finances, etc, every part of our lives, why would we not want him in the act that defines our marriage?
I love this teaching. As I said, I was not always that way, but when I learned that the Church had a reason for this teaching, I learned that maybe she has a reason for other teachings as well.