Bought an iphone. Still getting their iMessages

So I bought this iphone on eBay from some kids mother. And it is logged out of his iCloud and iTunes and I'm not sure why I'm still getting the iMessages. Is it the sim they left in it? I can't lie it's sort of interesting to read the txt this person is sending… Ahh. Need a life lol

Restore it back to factory, easy enough, that should be done anyways when buying a used iphone.

  • Why is my Iphone not sending as Imessages and receiving iMessages from one person? I'm texting my wife and we both have iPhone's and she is getting the messages as an iMessage but the ones I'm sending her on my end show up at green. Sometime it will go as blue, get the little red exclamation point then send as regular SMS. I'm texting someone else too and she has an iPhone, and she is getting mine as regular iMessages and mine are sending as regular iMessages. Why aren't they sending to me wife as iMessages?
  • Why do poor people care more about their image and buying nice clothes than feeding their family or paying bills? I see tons of poor people who make less than 20k a year spending their entire income on nice clothes and shoes and purses and makeup. Their children are starving they can't even afford to use the air conditioner or pay for electricity but they absolutely need to buy a new iPhone or a new pair of high heels
  • Why do i keep getting other people's iMessages? My sister got a new iPhone 4S and a screen popped up on my iPhone 4.It said something about getting imessage with 614-567-3879 (my sister's phone number) and so i though that meant whether i wanted to have iMessage when talking to her, but i didn't read all the way through. So i hit yes, and now whenever she sends a text to someone or somebody sends a text to her, i receive it to. How do i turn this off?
  • Is the iPhone 5s still worth getting in 2015? Is it getting obsolete? My mom might be considering on getting me an iPhone, but she said that i Can't get a 6. She might be getting me a 5s instead. I don't know when yet though. How many years will Apple support software updates? It is already almost two years old and is it still a worth getting?