religious ritual vs religious ceremony

religious ritual and religious ceremony both are nouns.

Word	Noun	Adjective	Verb	Adverb
religious ritual	Yes	No	No	No
religious ceremony	Yes	No	No	No

As nouns, religious ritual and religious ceremony are synonyms defined as:

religious ritual and religious ceremony: a ceremony having religious meaning

religious ritual (noun)	religious ceremony (noun)
a ceremony having religious meaning	a ceremony having religious meaning