Perhaps

Many years after the prophet Alma received a threatening message from an angel and turned his life around, the Lord sent him on a mission to call the Nephites to repentance. As he preached from city to city, he bore his witness of God's reality and of God's desire for the people to repent and turn to Him. Interestingly, he did not speak of his supernatural encounter with an angel as the basis for his faith and testimony. Instead, he spoke of the following conversion process:

Behold, I say unto you they are made known unto me by the Holy Spirit of God. Behold, I have fasted and prayed many days that I might know these things of myself. And now I do know of myself that they are true; for the Lord God hath made them manifest unto me by his Holy Spirit; and this is the spirit of revelation which is in me.
--Alma 5:46

It was not a visit from a heavenly messenger that converted Alma. The angel got Alma's attention, but it was fasting and prayer that brought the change of heart into Alma's life. While the angelic visitation was dramatic, Alma's conversion required diligence and patience. Alma had to wait on the Lord.

Why does God sometimes delay His response to my prayers? Perhaps He is giving me time to prepare for the answer. Perhaps I need the time to hone and refine my request. Perhaps I haven't done all I can on my own yet to truly distinguish between my power and God's power. Perhaps I am not ready to appreciate the answer when it comes. Perhaps I have taken no thought about what I want except to ask. Perhaps the development of patience and endurance are more valuable blessings than the thing I ask for. 

Nevertheless, once I am prepared, specific, and humble, having expended my own best efforts, and learned patience, the answer comes. It may not be what I initially thought I wanted, but it is always what I truly need.

Prayer Unlocks Power

When the prophet Alma in the Book of Mormon began seeing waywardness and wickedness in his son, he turned to prayer to engage God in the struggle for his son's soul. In response to the faith-filled prayers of Alma and the people of the church, the Lord sent an angel to halt Alma Junior on the path to destruction. The young man recorded the words of the heavenly messenger thus:

And again, the angel said: Behold, the Lord hath heard the prayers of his people, and also the prayers of his servant, Alma, who is thy father; for he has prayed with much faith concerning thee that thou mightest be brought to the knowledge of the truth; therefore, for this purpose have I come to convince thee of the power and authority of God, that the prayers of his servants might be answered according to their faith.
--Mosiah 27:14

Prayers on behalf of others work. They unlock the power of God. They don't necessarily change God's will, but they have an impact. 

Things happen with prayer that might not happen or might happen differently without prayer. I do not understand completely how it works or why it works, but I am convinced by many evidences that prayer for others does indeed work.

Honest Prayer of the Heart

When a young man by the name of Alma rebelled against wicked King Noah, he gathered many followers to whom he preached the true gospel. Eventually this band of faithful believers had to flee from the unrighteous kingdom. After settling in a secluded valley where they could worship God unhindered, Alma's people were discovered and surrounded by the Lamanites. Alma's people were enslaved, and along with losing their liberty, they were forbidden to worship God. Anyone caught praying to God would be executed on the spot. 

The scripture records how the people responded to their oppression:

And Alma and his people did not raise their voices to the Lord their God, but did pour out their hearts to him; and he did know the thoughts of their hearts.
--Mosiah 24:12

The Lord heard these silent prayers and answered them initially with comfort and strength to endure. Eventually, God rescued these people and led them to a place of safety.

The thoughts of my heart are more than my superficial musings. They are what move and motivate me. They are who I am when no one is looking. They are the essence of my character. To pour out the thoughts or contents of my heart is to be completely honest and transparent. No posturing or pretending. An honest heart is a broken heart. 

Honesty in prayer is essential. God knows when I am honest and authentic. I don't have to sugar coat it for Him. If I am angry, He can take it. If I am depressed, He comforts me. If I am happy, He rejoices with me and sweetens my joy. He simply wants to be a part of whatever I am doing and however I am feeling. If I invite Him in, He can enrich every moment. And in the end, He will save me and lead me to a place of safety, even into His loving embrace.