Command setting with permissions

[Axii]

Hello guys.

I have no idea how this code works. I have a command /becomechristian
I want people to be able to use it only if they are not in a religion. Like if player is already in a religion like "group.muslim" i dont want this command to be used.
If player has group.muslim, when player uses the /becomechristian command some title must show up and say "Hey you are muslim and you can not be christian!" something like this.

Please help.. ^^

command /becomechristian:
  trigger:
   if player has permission "group.muslim":
     send title to player "&6error" with subtitle "%player% blabla" for 5 seconds
   else:
     send title to player "&6CONGRATS" with subtitle "%player% ur now a christian!" for 5 seconds
     make console execute "lp user %player% permission set group.christian"

 

[Shroob]

command /becomechristian: # Hey since when is religion in minecraft
  trigger:
    if {religion::%player's uuid%} isn't set:
      set {religion::%player's uuid%} to "christian"
      # do stuff
      
command unbecomechristian:
  delete {religion::%player's uuid%}