There were many wars, sometimes about land disputes or something, but the main wars were the Crusades. The Christians wanted control of the Holy City of Jerusalem, but the Muslims controlled it. Both sides wanted it for religious reasons. The Muslims were fine letting the Christians come to Jerusalem and worship, but the Christians wanted it all to themselves. For over two hundred years the Christians fought with the Muslims over the control of the city.
Jerusalem
The Crusades were fought between Christians and Muslims. They fought in the Middle Ages, and actually fought violently. Both sides wanted to take control of Jerusalem.
GOD
they both are against witchcraft
The Holy Lands are important to both the Christians and Muslims. The crusades began when the Muslims began denying Christians access to the sacred sites.
Both a Christians and Muslims live in Libya. There are more Muslims there at this time.
The numbers aren't quite clear some say there are more Christians others say more Muslims both number over 1 billion but what is clear is that Muslims are a faster growing community than Christians. The most recent estimation I have seen is that Muslims number about 1.38 billion while Christians number around 1.42 Billion. needless to say there are a lot of both
The Jews. Here is the problem. Christians, Muslims and Jews have fought for control of that city for centuries. The Christians and Muslims actually do not have as bad a history as both against the Jews. The Jews have control of Jerusalem, but the reason is because they need their own country and are not really accepted anyplace else in the world. Not being sympathetic, just stating the facts.
Both Christians and Muslims are human and worship same God. They both prayed God to forgive them and save them.
I think both groups can use that name.
I think Jesus is both - prophet to the Muslims and god to the Christians. Both cannot be correct one must be right and one must be wrong. If the Christians are correct with their belief (John 10:30) - the Muslims will have some explaining to do. If the Muslims are correct with their belief (John 17:3) - the Christians will have some explaining to do.