Living_Oracles(i)
19 At that time the disciple came to him privately, saying, Why could not we expel the demon?
20 Jesus answered, Because of your unbelief; for, indeed, I say to you, if you had faith, though but as a grain of mustard seed, you might say to this mountain, Remove to yonder place, and it would remove: yes, nothing would be impossible to you.
21 This kind, however, is not dispossessed, unless by prayer and fasting.