He's got a point. Although if it was a muslim symbol up there, it wouldn't be Rick simply "questioning" or mocking the religion, but rather it would be a bunch of the members of this board calling the muslims terrorists, murderers, towelheads, and such.
IXQUS (Ichthys): Greek for "fish"
I Iota the first letter in the Greek word Iesous (Jesus)
X Chi the first letter in the Greek word Christos (Christ)
Q Theta the first letter in the Greek word Theos Of (God)
U Upsilon the first letter in the Greek word Yios (Huois) Son
S Sigma the first letter in the Greek word Soter (Savior)
Greek meaning Iesous Christos Theos Yios Soter
English transliteration ... Jesus Christ Of God Son Savior
Christians have been using this symbol since about 300 years AD, and we should leave it alone. It's a sign of faith, and shouldn't be meddled or toyed with.
It's roots can be traced as far back as the Pagan days. They used the symbol in their practice:
Ichthys was the offspring son of the ancient Sea goddess Atargatis, and was known in various mythic systems as Tirgata, Aphrodite, Pelagia or Delphine.
The fish also a central element in other stories, including the Goddess of Ephesus (who has a fish amulet covering her genital region), as well as the tale of the fish that swallowed the **** of Osiris, and was also considered a symbol of the vulva of Isis.
The fish also has been identified in certain cultures with reincarnation and the life force.
Before Christianity, the fish symbol was known as 'the Great Mother'...linked to fertility, birth, feminine sexuality and the natural force of women.
Regardless, it's a Christian thing now, so I respect it.