A couple using artificial means of birth control have taken God and nature out of the equation. As the article mentioned, it is used so that the woman can be available for sex at any time. Natural Family Planning actually involves being aware of how the woman's body works, and respecting that sometimes, if the couple believes they are not ready for a child at that time, it is not possible for the couple to express their love in the coital fashion. It requires folks to understand that their 'needs' may have to take a back seat for a couple of weeks. It isn't going to kill anyone to go without, it just goes against the grain of our immediate gratification society.