In Matthew 26:69-75 (also Luke 22:55-62 and John 18:17-18, 25-27), the Apostle Peter denied Jesus and lied about knowing Him. So why did he do this? The answer is simple. He was afraid. Of what was he afraid? Most probably he was afraid of joining Jesus in His trial before the Sanhedrin, which he knew was probably going to end in Jesus' death. Remember, Jesus had been threatened by the Jewish leadership many times before (Matthew 12:14, John 8:59, 10:31, 11:8), and undoubtedly Peter knew of this. So if Peter had identified himself with Jesus, Peter was most probably afraid he would join Him in His fate.