In the US, you may not fire people for religious reasons.
I ran into this twice, once in refusing to fire an employee who got df'd (the elders were upset with me, but did not remove me from MS position).
And once for hiring a person who interviewed with me, then got df'd before I could hire him.
I hired him anyway; he said he was going to meetings and working for reinstatement, good enough for me at the time.
The elders were now VERY pissed, told me anyone who hired a df'd person had no spirituality.
Still, no consequences against me.
And both employees kept stable work, were reinstated in a year or so. The elder father of one of the employees called me to thank me for hiring him.
They can't take any action against you for working for a df'd person, or keeping a df'd person on the payroll.
BUT they will breath fire and brimstone about it, making threats.
Contact a lawyer, my advice.
P