Having embraced Atheism in the early 60's and now retired, I can say that I have never been discriminated against, ostracized or persecuted because of that belief. There have been many polite conversations over the years with many religious persuasions and that's where it ended.
From time to time there would be that person who would feel compelled to wear his belief, as a badge with most conversations beginning and ending with, 'Jesus Christ'. Usually the work ethic of this person was buried under this belief and would eventually be terminated. It would be this person that claimed religious persecution and the reason for the termination.
This was also the claim of many who felt entitled due to the color tone of their skin or, in later years, ones sexual preference or some other badge of entitlement. For these people it was all about them and how they defined themselves was more important than the job, a work ethic and others.
For years the work place was a work place and although varying conversations of belief and identity took place, no one made the attempt to push those definitions on others. That is not to say that it did not happen. When an individual attempts to stand out and against the norm and FORCE others to accept 'his' convictions people automatically move to an attack mode, that is human nature.