How about this: Do you believe everyone who claims to be a Christian is, in fact, a Christian?
How about these guys, the Church of the Knights of the Ku Klux Klan?
What do we believe in our Church? We believe in the Bible before liberals translated it. We of the White Race came from Adam and Eve, not monkeys. The Bible clearly shows we are of one lineage, and makes reference to Beasts who walked on two legs. It also spoke of the wrongs of sleeping with these beasts. So we believe that blacks are not our Brothers and Sisters, but are beasts of burden. To accept evolution fully, is to say that we are equal with these animals, which history shows that we are not equal to, and in fact are superior to. While the Supreme Court has accepted animals to Vote and Marry with our race, we have not and never will accept this.They are a 501(C)(3) tax exempt religious organization. Do you think they represent the mainstream of Christian faith? Do you think they represent Jesus? Or do you think they may be Christians in name only?
Going out on a limb here to propose that most Christians would not agree to have the Church of the Knights of the Ku Klux Klan speak for them in matters of faith and practice — is it any further out on a limb to imagine there are Muslims who abhor and reject the hatred and violence of people who are Muslims in name only?