Saul was one of the witnesses, and he agreed completely with the killing of Stephen. A great wave of persecution began that day, sweeping over the church in Jerusalem; and all the believers except the apostles were scattered through the regions of Judea and Samaria.
Acts of the Apostles 8:1 NLT
https://bible.com/bible/116/act.8.1.NLT Search "Jesus Freaks Martyrs PDF," or related book, and follow Open Doors USA to see stories of martyrs. Romans 8:28, James 1:2-4