We are obligated to recite one hundred Berakhoth (blessings) a day. On Shabbath and Yom Tob as we know, there are less blessings in the 'Amidah and so we have to make them up by eating additional fruits and reciting Berakhoth on good smells, such as, "Boreh Aseh Besameem" on Hadas (myrtle).
Rabbenu the Arizal explains, that the twenty two letters of the Hebrew alphabet depend on these one hundred Berakhoth. If a person does not recite one or more of these blessings or doesn't say them correctly or says them but without the appropriate concentration, the corresponding letters are negatively affected. From this we see how important these one hundred Berakhoth are.
(See Ben Ish Hai, Shana Aleph, Parashath Wayyesheb, Oth Yod Dal)
