[randita]

After being freed, Centanni said: “We were forced to convert to Islam at gunpoint. Don’t get me wrong here. I have the highest respect for Islam, and I learned a lot of good things about it, but it was something we felt we had to do because they had the guns, and we didn’t know what … was going on.”

If he hadn't "converted", would he have been murdered, like Christians who refused to bow to the Emperor were burned like torches or fed to lions?

[muawiyah]

Yup, that's the rule. If you refuse to convert then they are directed to kill you.

's in the Koran

[zook]

"If he hadn't "converted", would he have been murdered, like Christians who refused to bow to the Emperor were burned like torches or fed to lions?"

It's not at all like that. The Christians you mention had no choice. They were going to be killed anyway. They didn't have the option of going back to a life in which they could freely practice their faith.