The phrase "ritual purpose" is correct and can be used in written English.
It refers to the reason or intention behind a ritual or ceremony. Example: The burning of incense served a ritual purpose in many ancient cultures, symbolizing the purification of the body and mind.
It probably served a ritual purpose in a royal court and was buried with its owner when he died.
It's a pilgrimage, and the expiation sought, the spiritual agenda, is "a ritual purpose: to exorcise the unthinking malignancy of the Dome, to celebrate the sprawl of London".
Studies offer new insight into the great monument's ritual purpose and meaning.
The reasons for this high variation may be temporary pooling and splitting of herds of closely related family members or aggregation of prior male cattle for ritual purpose before upcoming funeral and wedding ceremonies.
These channels were also used to carry water to the residential areas of the city, and it is possible that the channels also served a ritual purpose linked to the rain god.
Rum serves a ritual purpose in many parts of Madagascar, where it is traditional to throw the first capful of a newly opened bottle of rum into the northeast corner of the room as an offering and gesture of respect to the ancestors.
For ritual purposes the etrog must be perfect in stem and body.
They only kill the great predators for ritual purposes, or when threatened by them.
Other writings endorse the blood libel — the legend that Jews kill Christian children for ritual purposes.
The vessels will be placed in front of the portrait of the late Empress Xiao Qin Xian for ritual purposes".
They include practical adzes and axes; but some, made of semiprecious stone, were clearly intended for purely ritual purposes.
