Bereishit 1:1
Bereishit...In the beginning...
The Midrash relates that the Torah begins with the letter bet, rather than with the letter alef, because bet connotes beracha, blessing, while alef connotes arirah, curse.  The Holy, Baruch Hu, said, "I will begin with a bet, with an expression of blessing.  May it be that the creation will be able to endure."
Alternatively: The bet refers to the two [divisions of the] Torah, the Written Torah and the Oral Torah, to teach you that the world was created in the merit of the Torah and those who study it.
The gematria of bereishit (913) is equal to that of batorah yatzar, "He formed [it] with the Torah."  It was for the sake of the Torah, which is called the beginning (Mishlei 8:22), that the world was created.
Alternatively: The gematria of bereishit (913) is equal to that of yisrael bachar baamim, "He chose Yisrael among the nations" and to that of taryag yatzar, "He formed 613," indicating that He created the world for the sake of Yisrael, that they be enabled to observe the 613 Mitzvot.  It is because of those who observe the Torah that the world stands.  That is why Channah referred to them as "pillars of the earth" (1Shmuel 2:8) in her song of praise.
In the first verse of Bereishit there are seven words, corresponding to the seven days of the week, the seven years of the a shemittah cycle, the seven shemittah cycles of a yovel cycle, the seven heavens, the seven lands, the seven seas , the seven servants.  Corresponding to these, King David said, "Seven times a day I have praised you" (Tehillim 119:164)
And because of this correspondence, the Sages ordained that the refrain in the Kaddish - "May His great Name be blessed for eternity, for eternity of eternities" - contain seven words, and be recited seven times each day.  Moreover, in this first verse of the Torah there are twenty-eight letters, as there are in the refrain "May His great Name." 
As a parallel, King Shlomo composed seven verses - beginning with "a time to be born" and ending with "a time for peace" (Kohelet 3:2-8) - that speak of twenty-eight "times" [which correspond to the twenty-eight different time periods each week].  For there are four "times" in each full day-night period: From dawn to noon is one time; from noon to dusk is a second time; from dusk to midnight is a third time; and from midnight to dawn is a fourth time. [And so in seven days there are twenty-eight "times."]
Similarly, seven words and twenty-eight are also contained in the verse "G-d spoke all these statements, saying" (Shemot 20:1), [which introduces the Ten Commandments].  This [correspondence of letters and words between the refrain of the Kaddish and the verse that introduce Creation and the Ten Commandments] alludes to our Sages' statement, "Whoever answers...Amein.  May His great Name... with all of his strength (koach) becomes a partner with the Holy One, Baruch Hu, in the work of Creation."
-Baal HaTurim