These are buzz words in archaeology and is generally accepted, rather mockingly by most, that archaeologists cannot explain it or has no idea what is for, and they are sometimes ridiculed for coming up with ‘fanciful’ ideas with regards to ancestor worship or some form of deity.
However, ritual does not automatically mean association with a divine being or ancestor or supernstural power. Often when archaeologists refer to a ritual or ceremony they often referring to s secular practice, or at least a practice that has a secular function. A ritual is just a repeated behaviour done in a particular way.
I bet you perform many ceremonies or rituals that you carry out each day that are not religious in any way whatsoever!
I think sometimes it is worth remembering g the wise words of that great detetive –
When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.” —Sherlock Holmes