What do you mean "If I can"? Anything is possible if a person believes - Mark 9:23
At times, we need some assurance before we can take a leap of faith
The unnamed fatherhad seen Jesus' disciples fail miserably at cast ou the eveil spirit and wondered if the Master could do anything for him
Jesus fully intended to heal the boy but first dealt with the man's doubts
Though this may may not had enough faith to completely believe, Jesus could help him
If you want God to do great things in your life, you will need faith; don't be afraid to ask