This is exactly the crime, at least as the article reports it.
He didn't post them on the lunchroom bulletin board, he didn't picket in front of the building entrance, and he apparently was doing his work.
He posted his opinion on his own cubicle. We don't know if they were inside his cubicle or on the outside where visible to others.
If on the inside, then I would side with the employee.
If on the outside, he should have been told that that was open space that was not his personal work space, and that he should have taken his personal opinions inside his own space.
If it were my company, I would not want profane, racist, or dangerous messages in an open area. I would not have considered the bible verses to be any of those.
Straw man argument.