Do Christians have the power to rebuke illness?

There are many who claim that they can rebuke illness, the devil, and other things in order to prevent those things from doing harm to the Christian.  However, they are not using the term correctly.  The word rebuke means to express sharp disapproval or criticism because of behavior or actions.  The word in never used in the Bible as an expression to stop something from harming someone (Jesus did rebuke a storm, but this is an exception not the rule).  Each time rebuke is used it is to show someone they do not like what they are doing, pretty much scolding the person.  You can scold an illness, the devil, or anything you want, but that will not stop it from affecting you.  We must put our trust in Jesus and understand that things happen according to His will, not ours (Romans 8:28; 1 John 5:14).  We can pray for God to protect us from these things, and we can resist the devil, but rebuking will do nothing for us.