Answer:

It is not every day that I learn something brand new, but today is one of those days.  I was aware of only relatively indirect relationship between Christians and Muslims during Muhammad’s life.  But, having done some research, I can confirm that you seem to be referring to an actual event that happened in Medina in 632 AD, in which a delegation of Christians from the south of the Arabian Peninsula (perhaps from present-day Yemen) came to Medina to negotiate with Muhammad.  They had a “discussion,” which was probably more of a debate, in which the Christians tried to convince Muhammad that Jesus was God-in-the-flesh and was the Son of God.  If this were true, then it would have massively reduced the role and importance of Muhammad in his growing religion.  Not surprisingly, he rejected the Christian teaching that Jesus is God!  Instead, they settled for a compromise, in which Muhammad accepted that Jesus is the fulfillment of the Jewish messianic expectation, but that he is not deity.  He then pronounced a curse on all those who associate any person with God, which is the greatest sin in Islam. This sin is known as shirk.  Christians, who believe that a human being named Jesus was God-in-the-flesh are under this “curse” of Muhammad, even today.

After the stalemate in the debate/discussion, the Christians became intimidated, because the most powerful military leader in the Arabian Peninsula, Muhammad, was now a sworn enemy of them, perhaps not yet militarily, but certainly religiously.  Most likely, out of fear, they decided to sign a kind of treaty, in which Muhammad agreed to allow them to continue practicing their Christianity, as long as they paid a poll-tax (a tax proportional to the numbers of non-Muslims).  I assume, and the evidence supports this, that they did not fear the curse of God.  In fact, they simply disagreed with Muhammad, believing him to be a false prophet.  One does not fear the curse of one who is not a true prophet, as the curse of a false prophet is a false curse!  However, there was an element of fear for sure in them signing the treaty.  The fear was a military one, and to a lesser extent a religious one, as they negotiated at least temporarily not being persecuted.  Their fear turned out to be well-taken, as not long after the death of Muhammad, under the rule of Uthman, the Christians were persecuted and exiled from the Arabian Peninsula.

So, the answer is no.  Or perhaps more cautiously, very probably no.  They were not afraid of the curse but of the military leader Muhammad and his military and religious power.

John Oakes