How to activate iphone 5 ios 7?

I bought second hand iphone 5 with ios 7. The person who gave me this phone, he bought it from any other country. I don't know the person who used his icloud id to activate this phone. When i wanted to activate this phone, it shows me the massage that "A password is required to activate this device because it's owner has used find my iphone to link it to their apple id" please help me I'm very worried because i have paid for it.

I feel your pain, i bought 2 iPhones from a lady and i didn't know iOS 7 does that. So i have tried many different ways but it won't work. If you go to the apple store, they will most likely tell you to contact the original owner. If you are lucky they might do something, but i doubt it. As of now, your only shot is to contact the person you bought it from, because most likely that is his account that is on there. If that doesn't work then your phone is screwed.

The iPhone 5 features iOS, Apple's mobile operating system. The user interface of iOS is based on the concept of direct manipulation, using multi-touch gestures. Interface control elements consist of sliders, switches, and buttons. Interaction with the OS includes gestures such as swipe, tap, pinch, and reverse pinch, all of which have specific definitions within the context of the iOS operating system and its multi-touch interface. Internal accelerometers are used by some applications to respond to shaking the device one common result is the undo command or rotating it vertically one common result is switching from portrait to landscape mode.
The iPhone 5 is shipped with iOS 6, which was released on September 19, 2012. Many of the iPhone 5's features that work specifically with the included iOS 6.0 operating system only worked in certain territories on release. Apple has said this is a rolling program, which will take longer to implement across more regions.
The phone can act as a hotspot, sharing its internet connection over Wi-Fi, Bluetooth, or USB, and also accesses the App Store, an online application distribution platform for iOS developed and maintained by Apple. The service allows users to browse and download applications from the iTunes Store that were developed with Xcode and the iOS SDK and were published through Apple.
The iPhone 5 can play music, movies, television shows, ebooks, audiobooks, and podcasts and can sort its media library by songs, artists, albums, videos, playlists, genres, composers, podcasts, audiobooks, and compilations. Options are always presented alphabetically, except in playlists, which retain their order from iTunes.
http://www.NewiPhone5.co.uk
Users can rotate their device horizontally to landscape mode to access Cover Flow. Like on iTunes, this feature shows the different album covers in a scroll-through photo library. Scrolling is achieved by swiping a finger across the screen. Alternatively, headset controls can be used to pause, play, skip, and repeat tracks. On the 5, the volume can be changed with the included Apple Earphones, and the Voice Control feature can be used to identify a track, play songs in a playlist or by a specific artist, or create a Genius playlist.

You will need the owner to remove the device from their account or put in their password to activate. That is the security of this operating system. Could be a stolen phone.