There is much to be said, and then more, about the greatness of prayer in general but we will touch only upon several points in order to reinforce this exalted subject which is one of the pillars upon which the world stands.
Prayer is one of those exalted things which have supreme importance, as the Alter of Kelm noted, since prayer elevates a person. He explained that 'the world' actually refers to the person. Man is considered 'the world.' Prayer is designed to uplift a person and draw him near to the Master of the world. The Mashgiach, HaRav Yechezkel Levenstein used to say this repeatedly.
HaRav Shmuel Edelstein quotes the introduction to the Cuzari regarding the power of prayer. "The same way that the body needs nourishment, so does the soul require three meals a day. In the same way the soul needs replenishment three times a day, and prayer constitutes nourishment for the soul. This is the reason why Chazal instituted the three daily services for the soul.
"We similarly heard from HaRav Levenstein much more on the importance of the labor of prayer. He explains among other things that during the battle against Midyan, Chazal commented upon the words "a thousand per tribe, a thousand per tribe" that this comes to show that there were three groups of thousands: Twelve thousand to fight, twelve to watch over the supplies and twelve thousand designated for prayer as is explained there that even though this was a mitzvah battle which was guaranteed to be successful, nevertheless, twelve thousand soldiers were dispatched per tribe for prayer.
A large number indeed. Why? So that when the battle was won, the soldiers should not come to think that the victory was due to them. Each tribe was bolstered by a full thousand men who prayed for victory. Victory was not the result of natural means but due to prayer alone.
"And if then, in a mitzvah-war, there were so many set aside for prayer, how much more so do we, in today's dire situation, need prayers for victory!"
