Q 1:
What is the ruling on a Muslim who works as a guard of a church?
A:
It is not permissible for a Muslim person to work as the guard of a church because this involves cooperation with them in committing sins. Allah (Exalted be He) prohibits cooperation in committing sins as He (Exalted be He) says,
...but do not help one another in sin and transgression.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.