We left the premortal realm to come to this earth. We do not remember that time but our Heavenly Father has given us ways to remain in contact with him as we traverse the sometimes convoluted and difficult paths of mortal life. All people at times feel the influence of the Holy Ghost even if they do not recognize what they are feeling. Those who are baptized and confirmed members of The Church of Jesus Christ of Latter-day Saints are given the gift of the Holy Ghost to be with them at all times as they remember and keep their baptismal covenants. Our Father in Heaven has given us another way to remain in contact with Him - prayer. Through prayer we are able to thank our Heavenly Father as well as ask for blessings for ourselves or for others. Those blessings might be strength, comfort, knowledge of what choice to make, knowledge of doctrine, confirmation of truth, or any number of other things. The Lord told Oliver Cowdery: "Blessed art thou for what thou hast done; for thou hast inquired of me, and behold, as often as thou hast inquired thou hast received instruction of my Spirit" (D&C 6:14). Every time Oliver prayed, the Lord answered, even if he didn't recognize the answer. The Lord also said that Oliver was blessed because he had prayed.
Prayer seems like such a simple task. Some may wonder how something so simple can be useful. The Lord has spoken much about simple things: "[The Lord] sent fiery flying serpents among [the Israelites]; and after they were bitten he prepared a way that they might be healed; and the labor which they had to perform was to look; and because of the simpleness of the way, or the easiness of it, there were many who perished" (1 Ne. 17:41). All the poisoned Israelites had to do was look at a staff that the prophet Moses held but many thought it was too easy or wouldn't work. The Lord does much of his work through simple things: "Now ye may suppose that this is foolishness in me; but behold I say unto you, that by small and simple things are great things brought to pass; and small means in many instances doth confound the wise" (Alma 37:6). We shouldn't judge what the Lord asks us to do - we just need to do it. Prayer, which may seem like a small and simple thing, is vital for us to do. When asked what they can do to be a better person, many church members give what they jokingly call the Sunday School or Seminary answers: "Pray, read the scriptures, and go to church." We sometimes joke about them because they seem so obvious, so trivial. They may be obvious to many of us but they are not trivial.
Most revelation comes in response to prayer. Many blessings are received because of prayer. Through prayer we are able to secure the blessings of heaven. Amulek, missionary companion of the prophet Alma, taught much about prayer. He taught about both the blessings we receive through prayer as well as about what we should pray for. We can pray for mercy, our careers, our homes and families, our enemies, power against the devil, and our friends and neighbors (see Alma 34: 17-25). He taught that we should pray at all times and in all places - in our closets, our fields (workplaces), and our homes. Our hearts should be drawn out to the Lord at all times. Through our prayers Amulek taught that we will receive mercy and forgiveness (see Alma 34: 17).
Prayer also provides us with strength to resist temptation. In the Book of Mormon the Zoramites had become wicked and left the church. Alma and other companions went among them to try to bring them back to the truth. Among other problems Alma saw that they did not "continue in prayer and supplication to God daily, that they might not enter into temptation" (Alma 31:10). They had stopped doing the simple things and had fallen away. They hadn't just briefly let go of the iron rod, they were buying apartments in the great and spacious building and settling in. Constant and sincere prayer can keep us from temptation and sin. We should be in the habit of praying.
From psychological research we've learned that as we first practice something it might be difficult but over time it becomes easier and automatic. Think of riding a bike; it is hard to balance at first but soon you no longer have to think about what you are doing. Learning to drive a car is the same. After practice you don't have to think about what you are doing. Psychologists call these automatic processes. They require little thought or effort. They are also difficult to modify once learned. This is why when you practice something it is important to practice it correctly from the beginning. "Train up a child in the way he should go: and when he is old, he will not depart from it" (Prov. 22:6). Once you get into habit of praying it becomes harder to stop or modify the behavior.
The Savior taught much about prayer. He taught both with words and by example. Just as he prayed to his Father, so should we. The Savior however, was very critical of hypocritical prayer - of people who prayed to be praised by men: "Woe unto you, scribes and Pharisees, hypocrites! for ye devour widows' houses, and for a pretense make long prayer: therefore ye shall receive the greater damnation" (Matt. 23:14). Jesus taught the Jews on the mount and the Nephites at the temple about prayer: "And when thou prayest thou shalt not do as the hypocrites, for they love to pray, standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, they have their reward. But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father who is in secret; and thy Father, who seeth in secret, shall reward thee openly" (3 Ne. 13:5-6). Prayers don't need to be long (although they can be) but they should be sincere and honest: "When ye pray, use not vain repetitions, as the heathen, for they think that they shall be heard for their much speaking" (3 Ne. 13:7). Even though our Heavenly Father may know what we will ask before we ask (and He certainly knows what we need, even when we don't), it is important for us to ask. Also, because our Father knows what we need, we do not need to "use vain repetitions": "Be not ye therefore like unto them [the heathen, who use vain repetitions], for your Father knoweth what things ye have need of before ye ask him" (3 Ne. 13:8).
The Savior went on to teach those on the mount or at the temple how to pray (see 3 Ne. 13:9-13). What is called The Lord's Prayer is not meant to be a prayer to recited verbatim (although it is not wrong to do so) but rather, serve as a model of prayer.
It was because of the simple faith and words of a 14 year old boy that the heavens were opened and the gospel restored to the earth. Joseph Smith read the words of James: "If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him. But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed" (James 1:5-6). He not only read them but he thought about them; he believed them. He entered a wooded area by his home one spring day and knelt down to pray out loud - something he said he had never done before. As soon as Joseph Smith started praying, Satan came and sought to overpower him. I think there have been few times since the days of Adam when Satan had fought so hard with such great power to stop something. Joseph was ready to give in to the power of the devil when the Father and the Son appeared, rescuing Joseph from the Adversary. They came in response to Joseph's prayer and because of who Joseph was and would become. Few prayers are answered in such a manner as to Joseph's but all sincere prayers are answered. Joseph set an example of prayer.
In the Book of Mormon we find many examples of prayer. Among them is the prayer of Enos. Enos sought forgiveness for sins. He sought to understand what his fathers knew. He had reached a point in his life where he needed to put everything on the line, so to speak, and find out if the gospel was true, if the faith of his fathers was true. Enos prayed all day and night for forgiveness of his sins. When he had received that supernal gift, he prayed for his family and friends. Then Enos prayed for his enemies. Lastly, Enos prayed that the records he helped keep - the scriptures that would become the Book of Mormon - would be preserved. The prayer of Enos was sincere; he said he "pour[ed] out [his] whole soul unto God" (Enos 1:9). Enos arose a changed man. He immediately went back home and started preaching and prophesying.
Prayer becomes more powerful when coupled with fasting. The two activities are often spoken of together by prophets and in the scriptures. You can't have true fasting without prayer. The Lord has commanded us to fast and pray: "Also, I give unto you a commandment that ye shall continue in prayer and fasting from this time forth" (D&C 88:76). Fasting is also equated with joy: "Verily, this is fasting and prayer, or in other words, rejoicing and prayer" (D&C 59:14). Through prayer and fasting we can gain much strength. The sons of Mosiah experienced a mighty change in their hearts. They repented of their sins and became great missionaries. It is said of them: "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 17:3). They were blessed and blessed others because of their fasting and prayer.