All religions, except some forms of Buddhism, recommend prayer.
From the Latin precare, which means to beg, prayer is just that: begging, pleading, imploring a God, or some other otherworldly figure, such as a saint.
If your heart is made of penetrable stuff, seeing people in prayer will move you to tears. Why? Because prayer is perhaps the single most communicative gesture a person may enact, encompassing, as it does, all the hopes and wishes, all the longings and desires, of the entire human race, collapsed into the feeling and utterance of private or public begging.
Do you realize that most people you see, sometime during the course of their seventeen hours of daily wakefulness, beg the otherworld for something? Billions of prayers go up daily.
If someone earnestly begged you for something, on their knees and in a pitiable tone, wouldn't you be moved? Wouldn't you, moreover, if it were in your power to do so, grant the request?
It would depend, you say, on what was being begged for. People beg for guidance in major and minor life choices. Would you grant your guidance? People beg for health, for themselves and for children and for friends and family. Would you give them health? People beg for their lives. Would you extend their lives? People beg for forgiveness. Would you forgive? People beg saints to intercede with even higher powers. Would you intercede?
Some ancient currently dead religions and some variations of current living religions devise formulaic prayers for various uses and stitch and bind them together into prayer books. This religious sensibility invests each word of a prayer with efficacious power, so that the formula of the prayer cannot be deviated from without enervating the effect. In this view, God and the saints are persnickety judges of proper form.
Philosophical theologians have always been bothered by the notion that human emotion and words, evinced in the begging of prayer, can alter an immutable being such as God. Unchangeableness was supposedly one of God's perfect attributes. But if God answered a prayer, God would have been moved to...change. This was deemed a problem. The problem was solved through this clever construction: prayer does not move or change God but it puts the petitioner in a position to be moved or changed by God.
Smoke and mirrors.
It's no matter though because plainly most prayers go unanswered, having neither moved God, nor the saints, nor possibly even the supplicant. Were you to guess a billion prayers go unanswered for every one that is, you'd probably have a rough estimate of the reality. You yourself might always respond to a beggar, but obviously others will not.
A priest I know had a dream wherein the Pope witnessed God unresponsive to prayer. The priest's shrink said the woman in the dream was none other than God. Here is the dream:
The Pope watched a woman who was purported to be wise as she stood behind a curtain. People sat on the other side of the drape and were unable to see her. They importuned her about many things, for she was said to be powerful and generous and sapient and in possession of much knowledge. She did not answer all the people, however. At first she seemed to answer only those who called her by her correct name. Her correct name was Azra. But some called her Ella, and some called her Kiro, and some called her Brett, and some called her Lupe, and some called her Charise, and other names. She appeared not to answer questions from those who misnamed her. Later, she ceased answering those who did not evince enough emotion in the vocal delivery of their requests. She seemed to require passion in each query. Later still, she apparently answered only those requests that interested her, and these were few indeed. Finally, seemingly pococurante, she responded to no one. Brow to brow the Pope demanded of the woman why wisdom should be parsimonious and mute in the face of beggars. The woman responded in Latin: Taciturnitas stulto homini pro sapientia est. "For a dim person, silence is a substitute for wisdom."
Then the priest awoke. He subsequently left the Church. He married his shrink and is now busking on the Santa Monica promenade.
from 'An Opinionated Dictionary of Religion'