Many people may think that Islam spread by sword and because Muslims forced people to convert or they will be dealt with sword. even though the mecca's rulers back in the day rejected Muhammad and continued to torture Muslims. and when Muhammad went to medina, almost all of them embraced him and his message. the reason for Islamic conquests was to make sure they hear the message of prophet Muhammad. we all know there are countries in which non Muslims live with Muslims. Muslims don't make them to follow Islam. So this is enough to back the claim that people were not forced to convert to Islam but they are convinced of Islam.