The word martyr is from the Greek, marturion, which meant "witness." It was applied to the early Christians who, thanks to government persecution, often were killed because of their witness. Thus "witness" (marturion) came to mean "one killed because of his witness."
This means the islamic fruit salads who blow themselves up are not martyrs; they do not have their lives taken from them because they testify to the truth of islam. They are only murderers.
The reference was to the fact that the Copts and Orthodox under Moslem oppression know how to spread the Gospel without trumpeting their own horns.
Care to quote the part where we're told to go and convert other Christians?