Antivirus programs have done a very good job at keeping people paranoid so that they stay in business. You really don't need them now.
Yes, there are still plenty of threats, but the operating system itself, and its regular updates, keep on top of them...provided that you don't hang out on shady sites or download/install everything that strikes your fancy.
It didn't used to be that way, hence the market for third-party protection.
If you want to keep it, fine, but it's also fine to just turn it off. My experience, both with and without, indicates a ton of false positives, and no real threat anymore, that gets past an up-to-date OS itself and good internet practices.