My iphone 5 won't let me in without a sim card?

I just bought this iphone 5 from a friend and it was just fine but it had all my friend's pictures and contacts in it so I wanted to reset it and when I did it said sim card required. How can I get in without a sim card?

Give us some more information.

Sorry you can't. You need to get a Sim Card of the Carrier of the iPhone. If its a Att iPhone 5 then you need to borrow a att sim to activate it then you can just take it out after you get to the home screen. The sim can be active or deactive doesn't matter

I won't answer because its a apple product.