In reply to the post by the smearer of Catholics, below:
The source, "Answering Islam", is a Christian evangelical site that seeks to discredit Islam and convert Muslims.
Dallas Rourke is a hobbyist who includes in his papers a letter that tells Muslims the conditions under which they are allowed to disagree with him. He has a doctorate, he says, but he doesn't say in what, merely that he has an interest in comparative religion.
He also rejects the scholarship of the Jesus Seminar, a high-profile ecumenical group of New Testament scholars, because he doesn't like their conclusions.
I include the closing paragraph of Rourke's open letter, Dear Muslim:
I always look forward to hearing from people who read the articles. Let’s have a useful dialogue together. But remember the most important issue is not debate, but the good news of the Gospel that Jesus died for us to establish a new covenant of forgiveness. You don’t have to sacrifice lambs anymore. Jesus is the Lamb of God who makes the new covenant. Mt. 26:26-29. You can have a relationship with Jesus now. Pray to Him and you will know the truth. Don’t forget it.
With best wishes, Dallas
This is hardly an objective source, and hardly likely to seek out other objective sources.
Re: "common knowledge": It has also been common knowledge, at one time or another, that the Earth is flat, or that bad smells cause disease. Common knowledge is common, but it may not necessarily be knowledge.