"This man certainly performs many miraculous signs. If we allow him to go on like this, soon everyone will believe in him. So from that time on, the Jewish leaders began to plot Jesus' death." John 11: 47, 48, 53
"When all the people heard of Jesus' arrival, they flocked to see him and also to see Lazarus, the man Jesus has raised from the dead. Then the leading priests decided to kill Lazarus, too, for it was because of him that many of the people had deserted them and believed in Jesus." John 12: 9-11
The leading priests' blindness and hardness of heart caused them to sink ever deeper into sin, not to mention... that green-eyed monster - envy and jealousy set everything into motion. They rejected the Messiah and planned to kill him, and then plotted to murder Lazarus as well. One sin leads to another. It's like a domino effect. From the Jewish Leaders point of view, they could accuse Jesus of blasphemy, but Lazarus had nothing to do with that. They wanted him dead just because he was a living witness to Jesus' power. This is a warning to us to avoid sin. Sin leads to more sin, a downward spiral that can only be stopped by repentance and the power of the Holy Spirit.