Looking this week at Afghanistan… how would you respond when the Taliban comes to your house and asks for your papers and demands that you repeat the Shahadah: “There is no god but Allah and Muhammad is his prophet”
The Bible gives us the answer. Check out Persecution.

I have no problem recognizing that the God of Abraham is also The same God as Ishmael and that a prophet came from Allah. I don’t need that not-to-be true for them to take away anything from my relationship with Jesus. After all, Jesus didn’t say “Love your brother, except ….”
Your point about the “Shahadah” implies that it denies Jesus. Does it? I don’t think so. Now, if you ask that question directly — If I was asked to deny Him, like Peter, now, that’s a much more interesting question. I’d like to think I would face that question with His strength and courage (in the heat of the furnace). But, in some ways, each day is like that. I can chose to follow each morning, each moment, or chose to deny Him. I pray for strength to chose Him each and every moment.