Why pray if everything G-d does is good?

Question:
We trust that G-d knows what's best for us and does only good for us. Why, then, do we pray to change what is? Why are we trying to change what G-d gives--even if we don't see the good, it's good, right? Are we lacking in our trust and faith if we pray to G-d to change what is?

Answer:
This is a question with which philosophers have struggled time immemorial. Many answers have been given to this question, and I will attempt to give you some of the answers offered:
Prayer is G-d's way of allowing us to explain to Him how things look like from OUR perspective. From G-d's perspective--seeing the whole picture, of past and future, physical and spiritual words, etc.--everything is good and perfect and accomplishing exactly what is necessary. But prayer is G-d's way of saying to us, "tell me how things look like from your perspective in your world, and I will try to accommodate your perspective, by alleviating what seems like negative and showering you with more of what looks like positive." G-d, being infinite and omnipotent, can obviously accomplish the "good" of His plan while still doing it in a way that looks positive to us and that is openly revealed good. (See my essay Baby Talk for more elucidation on this subject.) Furthermore, prayer serves many different purposes.

The Hebrew word for prayer, tefillah, means self-judgment and introspection. Prayer is meant to be an introspective process. The reason why we pray is not always to change what G-d had intended for us, but for us to get a better picture of true reality. We might enter the prayers thinking about all that WE need and want, but we are meant to finish the prayers with a new realization of all that G-d does for us and how little we may actually deserve.

A person who experiences prayer as it is intended to be experienced, will finish off his prayers as a very different person than he began. The person who began the prayers (as a selfish, self-oriented individual) might not have really deserved what he was asking for, but the new person who concluded the prayers (as a thankful, grateful and more spiritual being) might now deserve it. In this way our prayers are actually answered, because WE change in the process and any negative decrees are then naturally averted.

Check out our Prayer Anthology for more insight on this crucial component in our service to G‑d.
Wishing you well,

Chana Weisberg for Chabad.org

Source: http://www.chabad.org/library/article_cdo/aid/524072/jewish/Why-Pray-if-Everything-G-d-does-is-Good.htm