Do I need service to use Imessage on an iphone 5?

So I my friend bought me an iphone that's unlocked, so I got a sim from T-Mobile and started to use it.
Soon I stopped paying my bills for T-Mobile because I had another phone. (KEEP IN MIND I ACTIVATED IMESSAGE AFTER I GOT THE SIM CARD AND IT WAS IN SERVICE, ALSO I SIGNED IN MY APPLE ID FOR BOTH IMESSAGE AND FACETIME) so after a while I went back to the iphone, It had no service because I didn't pay the bill but the sim was still inside. I turned off imessage and facetime because I didn't know it was free. Later on I turned it back on but when I did, it would either say waiting for activation (I THINK) or activation unsuccessful. Do I need service to activate it? If so how do I activate it with out a service?

Added (1). Please IGNORE THE TITLE AND READ THE DETAILS.

You need Wi-Fi to imessage but you can just text if you have service: D

People use imessage and facetime free without a plan all the time on ipads and ipod touches, you can use it on the phone too.

How do you text or facetime with no service like an ipod? Do you use you email address?