Help with a personal matter

[Shinylight]

Eilonnwy is right, there is no easy answer.

Your Dad's situation is very complex, it would be hard to give advice as I have had no experience with such.

All I can say is that you should look after him the best you can, question his faith, slowly at the start, and build up into more 'aggressive', in argument not in voice, and try your best not to make him stressed, at the first sign of such leave the topic dead.

I am not good at giving advice, you are probably best ignoring mine.