Question for Arab people!?

Ok me and my Friend which is arab had a discussion about egypt, he said that egypt is now mostly arab but then he said that arabs were the descended of ancient egypt which i found totally retarded and wrong, i know arabs came and invaded egypt in 638AD and egypt was almost at its downfall.. The ancient egyptians from Mizraim, Kush Empire ,Put and Canaan were his sons and the fathered africa, Arabs came from Shem, which he kept saying Ham.. Who could be this stupid trying to claim Egypt. anyways i asked him.. So if god ask you, are arabs the descended of ancient Egypt and if you give me the wrong answer you will die.. He told me to go home! =(