Original sentence: Many Christians converted to Islam after the Arab invasion, and at the end of the 12th century, the face of Egypt had changed from a predominantly Christian to a predominantly Muslim country.The Arab invasion of Egypt took place in 641 AD, and when the  Arab army under Amr ibn al-As conquered Alexandria, Christians were allowed to practice their religion, under the restrictions of the Islamic Shari'a law
Edited sentence: Egyptians fought with the Arabic swords and they helped Arabs to force out the Roman army, many pastors and popes return back to their churches and were treated in a good way.In the end of the 12th century, the face of Egypt changed from a predominantly Christian to a predominantly Muslim country and the Coptic community  didnt suffer any discrimination from the Muslim majority , many coptics were officers, leaders and statemens under the islamic rule, many of them were good merchants and had good relations with muslim merchants all over the islamic world.The entire Egyptian population didnt resisted the Arab Muslim invasion of 641.the  Arab army under Amr ibn al-As liberate Alexandria, Coptics were allowed to practice their religion, but many Coptics were converted to Islam