When Jesus said to them, “I am,” they drew back and fell to the ground.
At His arrest, Jesus shows His power over the evil men who had come to begin the events of His execution. He speaks just two words and they lose courage and fall to the ground. He states His identity not just as Jesus of Nazareth, but as "I AM"... the God of Israel's covenant. Jesus is clearly in control, even as the leaders of the religious elite move to take His life.
By stating His identity as "I am", Jesus is clearly claiming to be God. He has already boldly made this claim (John 8:58-59) and the Jews wanted to stone Him then. Now as they arrest Him intent on His murder, He states the truth that they hate one more time.
The crucifixion of Jesus was no accident. Jesus was no victim. He gave His life, as clearly seen here where with two simple words He stunned His accusers into momentary inaction. Had His hour not come, they could not have killed Him. But now, as the Passover Lamb gives up His life, He is the One clearly obeying His Father's will and giving Himself up for the sins of the whole world. He did so yielding to the will of the Father.