Before Jesus went to Heaven, He Taught His Disciples two great lessons in regard to their Relationship to Him in the Work they had to do.
The one was that, in Heaven, Jesus would have Much More Power than He had here on earth.
He would now Use That Power through His Disciples for the Salvation of men.
The other was that without Him they could do nothing.
Their First and Chief Work would therefore be to bring everything they wanted done to Him in Prayer.