If God is the source of all things good (love, light, connection, grace etc etc), being separated from him is to be separated from all things good. So imagine an eternity of being alone in darkness, disconnected.
Madness string 96995
First you tell a lie. Then you become the lie, and in time, the lie becomes you. Except at this point it's no longer really a lie anymore, because it's true, it's all true, and it's always been true.