What are some good answers to the Question if God is all powerfull what does he need our Prayers for? I would appreciate as many answers as possibile
Breishis 2:5 and Rashi says that the grass was ready to come out from the ground on the third day, however there was no rain since there was no man to realize the necessity of rain. On the sixth day Adam was created and he realized the value of rain. Only after he prayed for the rain, did it come down and make the plants grow. This teaches us that even if something is ready in Heaven for a person if he doesn't see the need for it which would make him pray for it, then he may not get it. Tefilah is something that is necessary for a person to obtain what he needs. Surely Hashem knows our needs without our asking, but this is His will and the way He deals with us. He wants us to realize what we need, that we cannot get them in any manner without Him, and to pray to Him for it. This is also for our benefit so that through this we can get closer to Hashem. Without Tefilah everything is frozen in place even though it is all finished and ready for the person.
Rav Chazkel Levenstein zt"l, in the Sefer Sichos Elul pg 64-68 writes about another aspect of Tefilah. Rav Chazkel points out how we are in a society that constantly preaches "Kochi V'otzem Yadi", (everything we attain is through Our might and Our great intelligence and not through Hashem). This influences us very much. Consequently, we need constant reminders that Hashem runs the world. That is what Tefillah and Brachos on food teach us. They are reminders of Emunah and Hashgacha. We constantly repeat, "You give us Knowledge..., You Heal us...,". Sh'hakol nihyah bi'dvaro - to believe in simplicity that "all is made only through His words". He concludes, "... likewise all prayer, has one goal, to ingrain the following principle in a person's heart "A person doesn't support himself in any way, all he needs is help from Hashem"." This will help us counter the constant barrage of "Kochi V'otzem Yadi" that we are submerged in.
Another aspect of Tefillah is the fact that it is very therapeutic and helps to calm a person's fears. A person has many problems and things to worry about. Some people even have to go to a psychiatrist and spend a lot of money, but it doesn't always help. We, however, only have to go to Hashem, and we don't need any money or appointments. Knowing that you are talking to the One Who is in charge of everything gives us a tremendous peace of mind.
A common question about Tefilah is, "Why do we have to Daven so many times, why not once a year"? This is similar to the question that the Talmidim of Rav Shimeon bar Yochai asked him. (Yoma 76a) "Why did the manna come down every day why not once a year"? He answered them with a parable. A King gave his son his yearly allowance in one lump sum at the beginning of the year. This resulted in the prince seeing the King only once a year. The King wished to see his son more often, so he decided to give him a daily allowance, forcing the prince to come by everyday. Likewise with the manna. Bnei Yisroel would worry every day that perhaps there would be no manna on the following day and they would die. This forced them to turn there hearts to Hashem everyday." That is why Hashem gives us the privilege of davening to him every day three times.
You should know, my brother, that the purpose of prayer is only desire for G-d and submitting before Him, that one elevates his Creator and praises and thanks Him, and throws all of his needs on Him.
("we pray to Him on our needs and troubles, even though nothing is hidden from His eyes, and He knows our needs better than we do, and He provides sustenance to all living things according to its deeds and according to what His wisdom decreed, nevertheless, we pour our prayers to Him in order to feel our great need for Him and our trust in Him, as the author writes in number 18" - Tov Halevanon commentary).
from chovos halevavos shaar cheshbon hanefesh chapter 3 way#9
One approach, that of the Nefesh HaHayyim, is to say that man is "omnipotent" too. God created man "in the image of Elohim [God]." The Nefesh HaHaayyim interprets this to mean that man was created with the quality of "Elohim", "takif u-va'al ha-yekholoet ve-ha-kohot kulam" "potent and master of all forces". God chose to give the power to man to cause effects through his prayer. Note that for the Nefesh HaHayyim prayer has nothing to do with material wish fulfillment in our lives; it is unselfish and for the sake of the universe as a whole.
The Mitzvah is n'geya b'atzmus... You could make the question stronger and ask why would G-d need any mitzvah from us?
Part of the answer is how we understand the word "need" and how we understand what "perfect" means. Part of what makes using the word "need" sound strange is they first think of like I "need" to eat or else I will die. That isn't a need but a weakness. What I need is to live and food just happens to be how I have to accomplish that. It's a means to an end. When we talk about "G-d's needs" they aren't weaknesses nor are means for Hashem to accomplish something to make him whole since Hashem is already whole and perfect.
Consider... If Hashem doesn't need anything there is no way to make sense of "ivdu es Hashem", there would be no way to make sense of the perkei avos "be as servants who serve the Master not to receive reward", there would be no reason to reward a person for fulfilling something that wasn't needed, if you were to tell someone to do something for you but you didn't need it and they did it they would actually be more distant from you not closer, when a person wants things they don't need we call them immature and Hashem is not immature
You say you'd appreciate as many answers as possible, so here is an interesting one. My understanding of Bernard-Henri Lévy's and Reb Chaim's position is that prayer is a way we somewhat brazenly, but successfully, defy darkness and forgetting:
Et puis, ces gestes de justice le plus souvent sans lendemain, ces étincelles minuscules et qui ne font pas feu, ces étoiles presque aussitôt avalées dans le trou noir de l’antimatière et du néant, il faut, troisième théorème, tout faire pour les stocker et, en quelque sorte, les mettre à l’abri. Et cela pour une dernière raison qu’a exposée, après Jonas et dans la brèche qu’il a ouverte, un maître que je cite souvent et qui s’appelle Haïm de Volozine.
Imaginons, dit-il dans son maître livre, L’Ame de la vie, un monde où il ne reste- rait plus un humain pour étudier la Torah. Imaginons le Livre, et les livres, tombant en déshérence, orphelins, esseulés. Imaginons un monde où le souci du bien au- rait disparu et où il ne se proférerait plus ni prière, ni étude, ni le moindre mot tendant vers le bien. Ce monde serait perdu. Ce serait comme une création à l’en- vers. Ou même une dé-création. Et ce serait un monde qui tomberait, littéralement, en poussière.
Mais, maintenant, l’inverse. Un Juste, un seul, qui lit quelque part la Torah. Une maison de prière, au bout du monde, avec une poignée de sages pour y prendre encore au sérieux la parole de Dieu. Une bribe de justice, ici. Un fragment de bonté, là. Un instant d’intelligence, encore ici, tel un vif-argent. Eh bien cela suffit. Car ce sont comme les poutres du monde. Ce sont comme ses chevêtres, fragiles, mal ajustés, mais d’autant plus essentiels, et qui, alors que Dieu s’est retiré, em- pêchent sa création de s’effondrer. Et les poutres gémiraient-elles, les faîtières ne tiendraient-elles que par sympathie provisoire et précaire, qu’il faudrait s’y tenir, et les tenir, avec une force et un soin redoublés – il faudrait tout faire, absolument tout, pour recueillir ces paroles et ces gestes, les emmagasiner comme on fait, pour le coup, d’un trésor, les stocker.
-- L’esprit du judaïsme, Bernard-Henri Lévy
And so. These acts of justice that in many cases have no future, these minute sparks that never catch flame, these stars that are almost immediately swallowed up in the black hole of antimatter and nothingness -- the third theorem is that one must do everything to store them and, in some way, to give them refuge. This for a reason that was put forth--after Jonah, in the breach that Jonah opened--by a master I often cite, Reb Chaim of Volozhin.
Let us imagine--he puts forth in his masterwork, The Soul of Life--a world in which there is no one left to study the Torah. Let us imagine the Book and books renounced, disclaimed, discarded. A world in which all concern for the good has disappeared, and not another word is pronounced of prayer, of study, or which in any way aspires to goodness. Such a world would be completely obliterated. It would be like creation in reverse: a de-creation. It would literally be a world returned to dust.
Now the opposite. Imagine that there is somewhere to be found a single upright person who is still reading the Torah. Imagine a house of prayer at the end of the world, where a few sages persist in taking seriously the word of G-d. A morsel of justice here. A particle of generosity there. A flash of intelligence still shining like quicksilver. For these are the joists of the world. They are like its crossbeams: fragile and ill-fitting, to be sure, but thus all the more essential--for when G-d has withdrawn Himself, they prevent His creation from collapsing altogether. And so much do the joists groan, so much do the beams hold only by virtue of some provisional and precarious sympathy, that they must hold on all the more, and one must hold on to them all the more. One must do everything, absolutely everything possible, to hold on to this speech and these acts: to protect them, to hoard them, to hold them like treasure.
For my part, I would hope and imagine that the very naivety of our prayer gives H' some pleasure.