That's the thing, that's not a common denominator if you really know what each group stands for and promotes. There are christians in Gaza under Hamas. There are different Muslim denominations in Gaza under Hamas. The other groups you are mentioning wouldn't allow this, they kill other Muslims for being different, and they attack christians. There is a huge contrast. What you call a common denominator is false. There are many "unbelievers" living fine in Gaza and in Palestine in general (ignoring that they are also being victims of Israeli attacks)