Expositor's Bible Commentary Commentary Mark 9:21

"And he asked his father, How long time is it since this hath come unto him? And he said, From a child." — Mark 9:21 (ASV)

Here Mark describes the deadly conflict between Jesus and the demonic powers. The demon immediately threw the boy, who had been sick since childhood and had experienced numerous vicious attacks, into a convulsion and made him fall on the ground and foam at the mouth. Pathetically the father asked Jesus for help. When he left home to bring his son to Jesus’ disciples, he apparently believed the boy would be healed. Now he was not sure and said, “If you can do anything.” 23–24 Jesus immediately fixed on the father’s “if” clause. The question was not whether Jesus had the power to heal the boy but whether the father had faith to believe Jesus could. The father responded with a declaration of faith, but he recognized that his faith was far from perfect. It was still mixed with unbelief. So in a beautiful display of honesty, he asked Jesus to help him overcome his unbelief.