What does Mark 15:43 mean?
"Member of the council" means Joseph is a member of the Sanhedrin, though we don't know if he is an elder or a scribe, a Pharisee or a Sadducee. Matthew mentions that He is rich (Matthew 27:57). Luke says that he is "a good and righteous man" who disagrees with the Sanhedrin's effort to crucify Jesus (Luke 23:50–51). John points out that while Joseph does follow Jesus, he does so secretly in fear that other members of the Sanhedrin will find out (John 19:38). The location of Arimathea is uncertain but is thought to lie about twenty miles northwest of Jerusalem. We aren't told why, if Joseph lives so far away, he owns a burial tomb just outside of Jerusalem (Matthew 27:59–60)."Took courage" is from the Greek root word tolmao. It has somewhat contradictory definitions in that it can mean to be bold or to build up one's courage. If the other members of the Sanhedrin find out what Joseph is doing, there's no telling what will happen to him. In addition, Roman law encourages that the body of someone who is executed should be further humiliated by being left to the animals instead of properly buried. Pilate would be culturally justified to leave Jesus on the cross, although if a relative asks for the body, the governing authority usually agrees. Still, people who are executed for high treason are usually left to the elements, and Jesus' charge is that He is King of the Jews in defiance of Caesar (Mark 15:26). Pilate would not release Jesus' body if he truly believed Jesus was guilty of treason.
Joseph needs to work quickly. Not only because carrying and burying Jesus' body is a work he cannot do during the coming Sabbath, but because of the nature of Jesus' death. The Mosaic law states that hanging on a tree is a curse, and Jews extend that interpretation to including hanging on a cross. The man is already cursed, but if he is not buried that day, the entire land shares in his curse (Deuteronomy 21:22–23).