Help what do I do ?
1. Your antivirus is blocking access to gs.apple.com.
2. Your phone is jailbroken.
3. Your computer has been used at some time in the past to jaibreak some iOS device (not necessarily the phone with the problem), and its network database was corrupted by the hacking software that was used.
4. Apple's activation servers are down (very rare, and never for more than an hour or so).
For 1. try disabling your antivirus.
For 2. & 3. you need to go somewhere other than an apple forum for help. Although for 3. you can try deleting lines containing gs.apple.com from your "hosts" file on your computer.
The hosts file contains overrides for IP address lookups when you go to a web site. To edit it you need Administrator privileges. For Windows you can use notepad (but not wordpad). For a Mac the best editor is nano, or vi if you know how to use it. You can use textedit, but that's trickier as you must change the default format to "unformatted". It's a hidden file, so you need to set up Windows Explorer or Mac Finder to show hidden files, or use the full pathname.
You need to use the sudo command to get admin privileges on a Mac:
sudo nano /etc/hosts
Once you have the file open you must delete any lines that contain gs.apple.com