Welcome to the Apple Support Communities!
I understand you are seeing an activation error on your iPhone 4s. Is this what you are seeing on your screen (iPhone is on the right)?
If so, then follow the steps in the resource below to resolve this issue:
Find My iPhone Activation Lock
If this is not the error message that you are seeing on your screen, then you may need to check with your wireless carrier to see if something is happening with your account:
If you can‘t activate your iPhone
Wireless carrier support and features for iPhone in the United States and Canada
Update your carrier settings on your iPhone or iPad
Take care.