If I restore my iPhone 4 to factory default will I have to jailbreak it again?

Some of my, well, safari, and other apps on my iPhone 4 crash right at the start of the app. Cydia, calendar, safari, maps, they all crash and I'm thinking about restoring it back to fix this issue. My phone is jailbroken but once I do that will I have to jailbreak it again?

The simple answer: Yes.