Are habits helpful or harmful?

I think that depends upon the habit.  Some habits are helpful.  Examples of helpful habits include our ability to tie our shoes without thought, brush our teeth properly with ease, get dressed, type messages, use a spoon, exercise, etc. 

Harmful habits may include mindless web surfing, too much time reading useless information and eating too much or the wrong types of foods.

According to John Ortberg in the Podcast: http://www.mppc.org/series/all/john-ortberg/healing-all-my-soul  habits cannot be overcome by willpower, but only by creating new habits.