Mark 10:27:

And Jesus looking upon them saith, With men it is impossible, but not with God: for with God all things are possible.

See also:

The Baseball Diamond of Healing
No Limits
No Big Deal: When Impossibility Meets Omnipotence
Objection: I Tried That Faith Stuff, and It Didn’t Work
Objection: Mental Illness Is Treatable but Not Curable