There is indeed a great ignorance here.
Christians are not to take the name of God in vein. While Allah is the Arabic word for God, the God of Islam is not the God of the Christians.
The god of Islam has no son. The God of Christians and Jews does. If Allah is said to be the same God as that of the Christians and Jews when Allah gave revelation to Muhammad more than 600 years after Yeshua, that Son of God that Allah did not have, then Allah would have delivered a false testament to Muhammad when he told Muhammad he had no son.
The god of Islam does not believe Jesus was crucified to die and take the sins of the world upon himself. That god taught this to Muhammad. Again, Allah would have born false witness to Muhammad were he the same God as delivered his only begotten son upon Mary so as to fulfill the mission of Salvation when Allah taught Muhammad that.
Allah taught Muhammad that the triune nature of God is blasphemous. And today Muslims agree. That is also contrary to the truth of the God of Christians and Jews. Islam also rejects that Jesus was God incarnate.
All these things, but not the only things,are in direct opposition to the cornerstone of the Christian faith that predates Islam.
If the God of Islam were the same God as that of Christianity then he'd be a man. Because his teachings to Muhammad make him a liar when he renounces what he said and did over 600 years prior when sending his only Son Jesus to earth. And then six hundred and more years later denied it all.
Numbers 23:19 God is not a man, that he should lie; neither the son of man, that he should repent: hath he said, and shall he not do it? or hath he spoken, and shall he not make it good?