Reconnecting To Hashem

The Rambam (Teshuva 1:1) says חַיָּב לְהִתְוַדּוֹת לִפְנֵי הָאֵל בָּרוּךְ הוּא, viduy must be done before Hashem.  Regarding Yom Kippur as well the Torah says לפני ה תטהרו.  What does it mean that viduy must be done before Hashem and why is it necessary?  Why is it that one who does teshuva is called a בַּעַל תְּשׁוּבָה, we don't call someone who wears tefillin a בעל תפילין?  

When one does teshuva one is not merely removing a negative, reversing his wrongs of the past but rather bringing a whole new light into his relationship with Hashem.  As the Rambam says (7:6) אֶמֶשׁ הָיָה זֶה שָׂנאוּי לִפְנֵי הַמָּקוֹם מְשֻׁקָּץ וּמְרֻחָק וְתוֹעֵבָה. וְהַיּוֹם הוּא אָהוּב וְנֶחְמָד קָרוֹב וְיָדִיד.  One who does teshuva enjoys a new close relationship with Hashem.  Why is this so?  

Rav Soloveitchik says every Jew has their own covenant with Hashem as being a member of Klal Yisrael.  Since there was a bris made with Klal Yisrael, a member becomes automatically part of this bris.  When one sins they are breaking this bris.  When one does teshuva they need to create a new bris with Hashem.  That is what it means viduy must be done לפני ה, one must reconnect with Hashem and personally recreate his own bris.  To create this new connection one must come personally to Hashem and ask to be given a new connection.  That is why such a person is described as a בעל תשובה, he is not merely one that has fulfilled a mitzvah of teshuva, he is someone who has established an entire new connection to Hashem. 

Rav Yeruchom Levovitz (Daas CHachma U'Mussar volume 2 #90, see also volume 1 #91) says that teshuva is not a means of refersing sin and therefore if one did many sins they need to do many acts of teshuva.  Rather, teshuva is a life changing experience.  One's entire service to Hashem now stems from teshuva.  He adds that is why Rabbenu Yona in Shaarey Teshuva gives a vast description of the mitzvot and halachot for a baal teshuva needs a new kabbalah of the mitzvot.  His new connection, new bris with Hashem, obligates a new acceptance of the Torah.  That is why the giving of the luchos happens on Yom Kippur for teshuva goes hand in hand with reaccepting the Torah.  That is why the Midrash says it is only Hashem that allows a sinner to do teshuva for it is only Hashem that has the capability of creating a new bris with the sinner.