Matthew 16:19:

And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.

See also:

YOU Can Do Miracles
No Limits
We Hold the Keys
Heaven’s Car Keys
The Insecure Preacher
If God Is So Loving, Why Doesn’t He Do Something About People’s Suffering?
Notes on Matthew 18:18-20