Matthew 27:20-21

The Sanhedrin members persuaded the crowd to insist that Pilate release Barabbas and crucify Jesus (cf. Mark 15:11). Initially this may seem incredible, but both Jesus and Barabbas were popular with the crowd. Pilate seemed to the people to be favoring Jesus’ release, but their religious leaders favored Barabbas’ release. It was quite natural that the Jerusalem people would side with their leaders against Pilate given such a choice, especially since Jesus was a "foreign" Galilean. The Sanhedrin had previously sowed doubts about Jesus in the people’s minds by circulating reports that He had blasphemed. To many of them He was now a heretic. Jesus Himself had failed to attempt what Barabbas had attempted, namely, overthrowing Rome’s authority over Israel. This may have been another reason the people wanted Barabbas released.