Some have argued that a religious exemption analysis in work-related cases might differ depending on whether (1) the job requirements changed in a way that violated the employee’s felt religious obligations or (2) the employee’s religious beliefs changed in a way that started to conflict with the existing job requirements. That might or might not be a good rule to adopt, but it’s not the rule that American religious exemption law has generally adopted. Here’s the Court’s statement on this, in the unemployment exemption context (though I think it would likely also apply to religious accommodations under Title VII), from Hobbie v. Unemployment Appeals Comm’n, 480 U.S. 136 (1987):
The Appeals Commission also attempts to distinguish this case by arguing that, unlike the employees in Sherbert and Thomas, Hobbie was the “agent of change” and is therefore responsible for the consequences of the conflict between her job and her religious beliefs. In Sherbert and Thomas, the employees held their respective religious beliefs at the time of hire; subsequent changes in the conditions of employment made by the employer caused the conflict between work and belief. In this case, Hobbie’s beliefs changed during the course of her employment, creating a conflict between job and faith that had not previously existed. The Appeals Commission contends that “it is … unfair for an employee to adopt religious beliefs that conflict with existing employment and expect to continue the employment without compromising those beliefs” and that this “intentional disregard of the employer’s interests … constitutes misconduct.”
In effect, the Appeals Commission asks us to single out the religious convert for different, less favorable treatment than that given an individual whose adherence to his or her faith precedes employment. We decline to do so. The First Amendment protects the free exercise rights of employees who adopt religious beliefs or convert from one faith to another after they are hired. The timing of Hobbie’s conversion is immaterial to our determination that her free exercise rights have been burdened; the salient inquiry under the Free Exercise Clause is the burden involved. In Sherbert, Thomas, and the present case, the employee was forced to choose between fidelity to religious belief and continued employment; the forfeiture of unemployment benefits for choosing the former over the latter brings unlawful coercion to bear on the employee’s choice.