I had a similar problem setting up my S7. After resetting several times and using all the other advice on disabling and restarting google services.
Here is another solution:
1) Log onto Google on your computer. Turn on two step verification to be texed to your phone.
2) Go back to the phone, select Google Services and attempt to log in
3) It should say log onto Google using your phone browser
4) Google will ask for your verification code (which will be sent to your phone)
5) Voila . . . then you can set up phone with Google and add accounts!
Here is another solution:
1) Log onto Google on your computer. Turn on two step verification to be texed to your phone.
2) Go back to the phone, select Google Services and attempt to log in
3) It should say log onto Google using your phone browser
4) Google will ask for your verification code (which will be sent to your phone)
5) Voila . . . then you can set up phone with Google and add accounts!