And you know that for sure, right?
No one’s ever un-believed?
Sounds like wanting to put God in a box.
I can't see how...Once you are filled with the Spirit of God, there's no provision for kicking the Spirit back out...Or, the Holy Spirit leaving...
One may turn from God, run from God...Get angry with God...One may deny God with his lips and even block God out of his thoughts much of the time...
But THAT Spirit is always there trying to get you back into the Grace of God...