Latter-day Saints are expected to be diligent in prayer, both in private and with our families. The purpose of prayer is to allow us to communicate with our Father in heaven and have a medium open between us and God through which we can solicit blessings from heaven. Genuine prayer is articulated in the sincere feelings and supplications emerging from a broken and humble heart. It stems from an inward appeal to seek in faith the blessings of a loving father.
When we do not practice the process of prayer, we deny ourselves the light and inspiration of His Spirit. We forego the feelings of gratitude that should fill our hearts and we disavow the desire to praise God for His goodness and mercy toward us.
Not only are we expected to pray but we are entitled to pray and ask of our Father for all things, whether temporal or spiritual, that we rightfully need. Modern-day revelation states: “Ye are commanded in all things to ask of God.”  The Lord’s Prayer teaches us that we should ask for “our daily bread.”  James urges us to seek wisdom.  Amulek advises us to pray over crops and herds, over fields and flocks, as well as for mercy and salvation. Nephi admonishes us that we “must not perform any thing unto the Lord save in the first place ye shall pray unto the Father in the name of Christ, that he will consecrate thy performance unto thee, that thy performance may be for the welfare of thy soul.” 
Clearly, we are expected to pray for all that we righteously and prudently need or desire. The Lord has promised the faithful: “If thou shalt ask, thou shalt receive….”  This does not, of course, give us the right to unwise and unlimited petition. All our requests must be based on righteous desires, and not on selfish greed or lust. As the Apostle James explains: “Ye ask, and receive not, because ye ask amiss, that ye may consume it upon your lusts”. 
We should seek for the gifts of the Spirit. We should plead for a more powerful testimony. We should ask for personal revelation. Most importantly, we should solicit the companionship of the Holy Ghost. When the Nephite apostles prayed, they “desired that the Holy Ghost be given unto them.”  The greatest gift we can receive in this life is the gift of the Holy Ghost. 
There may be times when it seems that the heavens are closed to us and that the Lord does not answer our prayers despite the promise that “whatsoever thing ye shall ask in prayer, believing, ye shall receive.”  A careful examination may reveal the reasons for this seeming contradiction.
Prayers we thought were unheard and unanswered may have been answered through spiritual promptings and feelings that went unrecognized because we were insensitive to them.
Answers may be delayed because God wants us to study, search and ponder more before He does respond.
It could be that God is simply waiting for us to decide first before confirming that decision through the Spirit.
God will always respect our free agency as well as our spiritual knowledge and understanding. Sometimes He allows us to decide and act for ourselves.
On the other hand, God may postpone a response if we are too spiritually immature to acknowledge or accept His answer.
Some prayers go unanswered because they are simply contrary to the will of God.
We should always be patient and remember that we may not receive an answer to our prayers until our faith and perseverance have been tried and tested. Instead of questioning or losing faith in God over seemingly unanswered prayers, we should evaluate our own intentions and purposes when praying and strive to develop a deeper spiritual sensitivity to the voice of the Spirit.
In his book, Receiving Answers to Our Prayers, Gene R. Cook assures us that:
“1. God listens to our prayers and answers them. (See D&C 98:2-3; 88:2.) I believe there has not been one sincere prayer offered by any man since the ‘beginning’ that has gone unanswered.
“2. God lives and loves us and will give correct answers to all sincere prayers, no matter what the question is. (See Moroni 10:4-5.)
“3. We are children of God and servants of the Lord. We can pray as Samuel did: "Speak; for thy servant heareth." (1 Samuel 3:10.)
“4. It doesn't matter how old we are, or what our Church position is, or how long we’ve been members of the Church. The Lord desires to answer our sincere requests regardless of these things.” 
Sincere prayer, practiced on a regular, consistent basis, is the most prevailing and influential force for putting us on the path of spiritual development and for keeping us on the narrow road to righteousness. The rewards of honest and purposeful prayer will be an inexpressible sustenance to our souls.
 Alma 33:8
 D&C 46:7.
 Matthew 6:11.
 James 1:5.
 See Alma 34:17-29.
 2 Nephi 32:9.
 D&C 42:61.
 James 4:3.
 3 Nephi 19:9.
 See D&C 14:7.
 Matthew 21:7.
 Cook, Gene R., Receiving Answers to Our Prayers, Deseret Book Company, Salt Lake City, UT. 1996.