Apple ID, Active Devices & imessage,

Thank you Eric, for various reasons I do not use icloud and do not have it enabled, what puzzled me was why the phone was still showing as signed in on my apple id page after I had logged out all apps, was not signed on the phone, logged out of my apple id account 3 or 4 times and kept seeing the phone as an active device. Even when I completely removed the phone from my list of active devices imessage continued to work as normal, i turned imessage off, waited a bit then turned it on, I received a message saying my login and password needed to be updated along with option button "not now", when I select not now the request for login and pw goes away and imessage functions as normal, this is completely contrary to everything I have read, apples own info says if the phone is removed from active devices in my apple id page then apps and services will not work, my concern is security related, not disabling imessage per se, thank you again for your time,