what do this quote mean that Demise be a formal affair?

I don't know what "Demise" refers to. A formal affair is a party or occasion at which long dresses are worn by women and tuxedos are worn by men.

demise means death, how do death be like a party?

Ohhh! I see now.

I think it means that death is a solemn occasion and deserves a formal ritual.

so that mean it deserve to be given honour to?

Yes. You've said it very well. :-)

thanks ms. sue :)

You're welcome, Mohammad.