Guys follow the instructions. It asks you to connect the phone to itunes to use push notifications. Just follow the instructions. You don't need to restore or reset the phone. Just connect to itunes and do a sync
I had the same issue after installing iOS7 on my iPhone 5. Did a backup (at the new iOS7 level); did a factory restore; did a 'Retsore from iTunes backup" when the option arose - all seems to be working.