The only reason i could think of that they would have brought Jack out to see the funeral (which seemed to suprise Juliette) was to show them how civil they really were.

I guess i didn't really see the ceremony as cult-ish in any way. Though odd that they set the raft on fire, i thought their white robs simply symbolized purity or good intentions...something along those lines. I guess this is reinforced in my mind due to the fact Ben had Jack put on the robes as well. He wanted everyone to represent the same thing. I have no first hand experience, but it seems like in cult settings, they only want people who are a part of their cult to dress like them/attend such a ceremony.