You honestly think using withdrawal is effective? Not to mention condoms and spermicides? These things are very far from being 100 percent effective. Please, do me a favor. Look up what the effectiveness rate is for each of these methods. Now do some math, and think about what would happen if, for example, every fertile and sexually active couple depended on one of these. Spoiler: Any one of those methods would keep dozens of abortionists busy from dawn to dusk.

Even more effective methods like the pill DO fail sometimes! Talk to a few women. Contraceptive failure is extremely common.