John wondered at the thought that there would be a time in the future when a group identifying as Christian would put others to death for having faith in Christ.
A martyr is one who is killed for his faith. Only two individuals are specifically named as martyrs in scripture: Stephen and Antipas.
There is one murder that far surpasses every other murder ever committed. That particular murder occurred when Jesus Christ was crucified.
At times, God called people to enter into war with the goal of killing their enemies. The Bible clearly distinguishes between this type of killing and murder.
God places a high value on life. His desire was for man to be fruitful and multiply and bring forth abundantly in the earth (Genesis 9:7).