Christianity was born in the blood of the Lord Jesus Christ which was shed on the cross for the sins of mankind. Later followers of Christianity ended up choosing their blood be shed for their faith as proof of genuine conversion. The more Christianity was persecuted in cold blood, the more Christianity grew instead. It has never been a religion that called for the shedding of blood but rather shed your blood if you have to in order to win others to Jesus.
Islam has the very opposite. They teach that it's blasphemy to believe that Jesus died for the sins for sinful humanity, that people are on their own and some Muslims even believe to appease their false god Allah, they must shed their blood. Islam expanded by bloody conquests and persecution of those who refuse to submit. This is very different than what Christianity teaches about loving one's enemies, praying for those who persecute you and even dying for your worst enemy so they'll come to see how different the Lord Jesus Christ is from the false god of Islam.