Alma 17

 As the sons of Mosiah began their Lamanite callings, we learn they - 

"...they were men of a sound understanding and they had searched the scriptures diligently, that they might know the word of God.

3 But this is not all; they had given themselves to much prayer, and fasting; therefore they had the spirit of prophecy, and the spirit of revelation, and when they taught, they taught with power and authority of God."  (Alma 17:2–3)

I believe that this is the pattern to receive revelation and power in our callings.