I have a stolen iPhone 5c but I didn't know it was stolen?

I bought an iPhone and checked the imei and I found out it was stolen. I can't use it yet because it is stuck in the beginning where it says " please insert a sim card, SIM required" I just want to use it as an iPod since I got it for a good cheap price. It is a sprint phone, and also if I take it to Apple or Sprint will they take the phone away? I didn't know it was stolen and I don't want to get blamed or end up losing money.

Added (1). The iPhone was restored already.

We aren't here to help you STEAL.

Insert a sim and try to activate without a carrier to use just Wi-Fi. ICloud activation lock might be on there and ruin your dreams of an iPod. Honestly Applestore or Sprint doesn't care. They don't get involved in third party purchases or disputes. They sell phones, new phones. Be advised when you turn it on and if iCloud activation is installed it could be pinging it's location back to the original owner for the 'Find my iPhone' feature. With the IMEI burnt, they probably don't care anymore. Best luck.

Return the phone, if you get caught you will get in trouble for handling stolen goods even if you didn't know of was stolen.
Also, do the right thing, the phone belongs to someone else and who knows, maybe the people will let you keep it.