I bought I phone 5 closed icloud how to resolve this issue

An iCloud locked phone is a parts phone unless you can contact the original owner for their credentials to clear the lock.

parts phone. sell on eBay

Mohame Mousa wrote:

I haven't any contact with the owner,so please help me

The the phone is useless to you. There is no way to bypass activation lock without the cooperation of the person who set it.

It isn't even that good for parts, because the logic board, which is the most valuable part, will remain locked.