Naomi - "andy-hughes, //This lady is not (potentially) looing her job because of her religious primciples, she is losing her job because she will not perform the tasks that the job involves.//
That makes no sense. She is refusing, solely due to her religious principles, to carry out the tasks her employer requires of her. Therefore she is losing her job due to her religious principles. If she wasn’t Muslim she’d serve passengers with alcohol, just as she did before she converted to Islam, and her job wouldn't be in jeopardy."
I know it appears to be hair-splitting, but I do believe that the distinction is valid and important.
If the lady said she was not serving alcohol because her father was a violent alcoholic, then she would face exactly the same sanction.
The point is that the sanction is imposed because of the unprofessional behaviour - the reasons behind that behaviour are not an issue as far as the employer is concerned.
The employer expects tasks involved in a job to be performed, and if they are not performed, there are sanctions, including dismissal at their disposal.
The reasons why the tasks are not performed are of no concern, or relevance in terms of enforcing an employment contract.