The 'amida is the most important prayer. It was composed by anshe keneset hagedola, the Men of the Great Assembly during the Fifth century BCE. The words of 'amida are extremely significant, second in their importance only to the words of the Tanakh (the Hebrew Bible). The text of the 'amida was also formulated in a very precise and sophisticated structure, as follows.
The 'amida contains 19 berakhot, or blessings, each blessing is dedicated to one theme. The 19 blessings are divided in 3 sections.
(3) The first section, "Praise", contains 3 berakhot. In this section we are not asking, nor soliciting anything from God. We begin this prayer by praising Him, declaring that we are aware that He protects us, as He shielded our ancestors. We also acknowledge that our physical survival is entirely dependent on His benevolence (hesed, rahamim).
(6.6.1) The second section, "Requests" contains 13 blessings. In these blessings we ask God to fulfill our needs. The first 6 blessings of this section we focus on our basic personal needs. We ask God to give us wisdom, health, a decent livelihood, etc. The next 6 berakhot focus on our national aspirations. We ask God to bring to fruition, soon in our days, redemption (=coming back to Erets Israel), having the right political leaders, re-building Yerushalayim, etc. The last berakha of this section, shome'a tefila, contains a general and comprehensive request. We ask God to listen to all our previous pleads. At the same time, because this berakha does not focus on any specific theme, it allows us to beseech God for any particular requests that might not have been covered in the previous berakhot (for example: finding the right wife/husband, having children, etc.).
(3) The Third section, "Gratitude", contains 3 blessings: The middle blessing of this section, Modim, is a prayer of gratitude to HaShem. In the blessing that precedes Modim, we ask God to restore the conditions which will allow us to worship Him once again in His Temple with prayers and sacrifices. Finally, in the 19th and last berakha, we ask HaShem to bless Israel with peace. We end the 'amida asking for peace, "shalom" because peace is the Jewish people's highest aspiration, personally and nationally, and the most encompassing of all of God's blessings.