Alma Chapter 17

17:2-3 - "...but this is not all; they had given themselves to much prayer, and fasting..."
If we want blessings, most of the time there is a required price to pay.
In this case, if we want the spirit of prophecy and the spirit of revelation, it is not enough to search the scriptures diligently - we also must give ourselves to much prayer and fasting.
Great blessings - and a great price - but both blessings in and of themselves.


17:9-12 - "...that they might be an instrument in the hands of God to bring, if it were possible, their brethren, the Lamanites, to the knowledge of the truth..."
This is why we are here on earth - to help all those around us to come unto Christ (Alma 29:9).  We can do this by being effective instruments in the hands of God - by letting virtue garnish our thoughts unceasingly, following the spirit, and applying Alma 17:2-3.
Elder Erich W. Kopischke talked about this in the November 2007 Ensign, Pg. 33-35 - he talked about the Preach my Gospel manual, and how it can help us become better instruments in the hands of God.  "If we want to learn as missionaries do, we too must carefully study Preach My Gospel and observe the missionaries in their daily work."
As we put in the effort, we will receive those blessings.

17:9-12 - "...they fasted much and prayed much that the Lord would grant unto them a portion of his Spirit to go with them, and abide with them..."
The Sons of Mosiah prayed in faith to be instruments in the hands of God.  The Lord visited them with His Spirit and comforted them.
As we work to be obedient and faithful in our responsibilities, we will pray in faith to do better in our callings.  We will receive instruction and comfort to help us do better.  It's a great blessing that requires faith.