That's true. Christians do know this.
Non-Christians bait the issue and hope like all get out that those they hope to persuade are stupid.
If allah was the same god as that of the Christians Muslims wouldn't make news in the middle east having cut the heads off Christian children for not converting to Islam.
They'd not make news having slaughtered Christians because those Muslims would concur that they're all worshiping the same god just having different beliefs.
The blood that flows in the middle east, and in America too when muslims make the news killing Christians, proves that it is not a same god different faith matter for those muslims. It is a different religion all together. And the obvious fact supporting that is that Christians don't believe Muhammad is the way, the truth, and the life. Nor is there a single scripture in the new testament that says, no one comes to the father save through belief in the mortal immoral man, Muhammad.
See, if it was the same god, then that god is insane.
But the Bible tells us God is not a man that he should lie.
If that God that said that is the same god as is that which is worshiped in Islam, then god in the Bible did lie!
He's insane and he suffers a combination of multiple personality disorder with amnesia.
For the god of Islam to be the God of the Christians and the Jews, remembering that Islam arrived in 622A.D., that's key too, that god would have had to, in order of appearance, told the Jews he would send a Messiah to save the world. Then , per the new testament testimony, he would have fulfilled that prophecy through Mary and delivered Yeshua, who was God incarnate, to the world. In what is said to be 1A.D. or as some scholars theorize the year 6 or 7A.d.
Then Yeshua would have had to deliver his message of salvation to the people of the middle east, told them that no one comes to God the Father but through belief in him and following the plan of atonement, redemption, salvation, that Yeshua taught in the course of his ministry. And then he'd have to die on the cross so as to deliver the message of the cross, the final sacrifice as he became the propitiation for our sins. He'd then have to be laid to rest in a tomb, rise in three days, walk the earth for 40 days and ascend to Heaven.
Then in 622A.D that same god that arranged all that, would have to forget the whole thing! Vacate Yeshua's status as his son, relegate him to the status of minor prophet, and slave to himself on earth, while sending an angel to a thief, a rapist, murderer, a pedophile, and an illiterate merchant named Muhammad so as to tell him to come out of his hut and mount a winged horse because that god wanted to have a chat.
And complying, that illiterate merchant, rapist, thief, murderer, and pedophile, would have then been flown on the back of that horse to allah's heaven so as to be told the story of how the pagan polytheists in the middle east, remember over 580 years after the middle east was being converted to monotheism and Christ, so as to believe in allah. Who is one god, no trinity, no son, and who's only prophet would be that illiterate, rapist, thief, murderer, pedophile.
That's what you'd have to accept as true in order to believe the God you worship today is allah.
You'd have to believe that the God you worship is insane! Suffers multiple personality disorder and amnesia.
He sent his son, himself in flesh, to save the world. Then he sent an immoral illiterate merchant to teach everything that contradicts the first prophet named Yeshua/Jesus, whom he then taught was not his actual son but was his slave.
And then he'd have to teach through Muhammad there is no baptism, there is no repentance, and of course, Yeshua did not die to take the sins of the world upon himself.
Yep, that's what you'd have to accept in those 'different beliefs' about the 'same' god if you accept that the God you worship as a Christian is the same one as is worshiped by muslims.