Here’s an analogy that someone gave me to better understand the difference between NFP and ABC.
The natural purpose of eating is nutrition and sustenance. There is a pleasure that comes along with eating. If you want to eat ice cream, cake, or any other tasty foods that aren’t very good for you then you have to eat responsibly and practice self control. Eat healthy foods during the week and exercise and reward yourself every few days with a good desert or junk food. We have the technology to analyze the nutritional make up of food (carbs, proteins, starch,etc) so that you can decide what you should and should not eat and how much of what etc.
NFP is like this responsible way of dieting while birth control is like bulimia. NFP respects the purpose of the act, you’re playing by God’s rules. God gave a woman infertile times and we now have the technology to track those times just as we have the technology to to see what nutrients are in foods so that we can eat right, but have a treat when we’ve eaten healthy. The church doesn’t say that it’s wrong to have sex for pleasure, but you can’t alter the for your own pleasure.
Birth control is similar to bulimia in that the person pursues the pleasure of the act without accepting the natural result of their decision to perform the act. NFP requires you to be virtuous, it requires you to be temperate and practice self control. To me this just makes sense because it agrees with “everything in moderation”
I’m not trying to judge anyone who uses birth control, I just wanted to try and illustrate the difference between the 2. For a LONG time I didn’t see the difference at all and was really confused about what to think. I hope this helps.