1- Do you know any thing about Abrahim (Abraham) Alahey Salam the ancestor of all Jews, Christians and Muslims [hmmm] (may be u don't), search 1st, study something about him n then discuss this topic. I think you may not aware that neither of these religion teaches pegan worshiping.
2 - Now you are able to check the claim that Makkah is the Center of the Earth so you can easily understand why every Muslim face towards it during "prayers". For simplifying it for you, we do this because:
a- Allah has command us to do that.
b- Every Muslim show unity while performing prayers that no matter what (he/she is from Shia or Sunni school of thought) his/her direction ultimately (in the end) is one.
c- Its only use as a direction, as Kaabah is our Qibla (In arabic means direction).
The black stone is out side not in it
(you need a lot of study and evolution) :twisted: