"Ah, but then they aren't worshiping correctly now are they." PM

According to their own scripture they are.
The Holy Qur'an says:
"... slay the infidels wherever ye find them..." Holy Qur'an: Sura 9 Verse 5

And according to what I've read, some Muslim on Muslim murder is religiously justified on this basis, each sect (Sunni / Shi'ah / Wahab) considering the others infidels for not worshiping the way they do.

"when the bigots of this world have been privileged for as long as they have, to them equality feels like discrimination." shiftless2