One day, all who know the Lord as Saviour will cease from their labours. It will be a time of eternal rest experienced only by those who are born again.
The Lord commanded the apostles to separate themselves and rest a while. Each believer today should examine whether is obeying this command of the Lord.
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.