Lost mode asks me for my passcode but i've never had one. What to do!?

Hello everyone,

I found my iPhone after using the Find My iPhone app but now it's asking me for a passcode. Thing is, I have never placed a passcode on my iPhone 4s so how on earth am I able to access my iPhone now? My last back up was a little over a year ago too... I think i have the latest iOS 7 because I never went to iOS 8 because of my phone not having enough memory.

If I have to do a backup right now to wipe my iPhone (while it's locked), will I be able to reset my iPhone, retrieve the back up (that i will do today), and bypass this locked mechanism?