We have arrived at a point where it behooves us to explain the internal significance of the luchos. Our explanation is separated into two parts. The first part starts with the famous statement that "Love your neighbor as yourself" is the overarching principle that encompasses the whole torah. The question is famous: We understand how this mitzvah encompasses all of the laws governing interpersonal relationships but what about those laws that govern our relationship with Hashem? How are those laws covered by "Love your neighbor as yourself"?
The explanation is as follows: In the world of teshuva we are required to ask our friend for forgiveness in order to make amends and fix what we did wrong. We fix the hurt we caused our friend by appeasing him and removing the feeling of anger he rightfully has towards us. This requires us to explain the mitzvah of vi'ohavta li'rayacha kamocha: In addition to the mitzva of loving our friend we are also required to be loved by our friend. Since the nature of a person is that when he loves someone he also wants to be loved in return, it makes sense that the mitzvah of loving your friend includes the effort a person invest to ensure that the love be reciprocated. It emerges then that every sin between man and his fellow includes two distinct violations of the mitzvah of vi'ohavta: A] He caused harm [emotional or otherwise] to his friend. This is a violation of the mitzvah to LOVE ones fellow. B] He gives his friend the halachic right to have a complaint against him. This is a violation of the commandment to be loved. When he appeases his friend he in essence removes his friend's right to be angry with him. For if his friend refuses to forgive him he is called a "cruel" person. In this way, the act of asking for forgiveness fixes the evil that had been perpetrated.
In the mishna in horiyos we find that there is a list of people who take preference when it comes to saving lives, for example a talmid chochom takes precedence over a non-scholar. We see from this that there are levels of "reyus" [friendship] and the bigger the "raya" the more one is obligated to love him and save him if necessary [see Maran's eulogy of R' Chaim Shmuelevitz – A.E.]. Here we find the place where the mitzvos between man and G-d are encompassed by the mitzvah of loving your friend. For the mitzvah of loving others includes the mitzvah to be loved by others. Every bit of growth in Torah obligates others to love one more. He becomes a bigger "raya". So we see that a person's investment of effort in torah [a mitzvah between man and G-d] obligates others to love him more and we have before us then a fulfillment of vi'ohavta li'rayacha kamocha through the fulfillment of mitzvos between man and G-d.
WHOA!
We have now arrived at part two. The Rambam in the seventh perek of hilchos deyos says that we are obligated to walk in the derech Hashem which he defines not as the path on which we are commanded by Hashem to walk but rather the path on which Hashem Himself walks. After revealing this gem we reveal yet another gem. The secret of the fatherhood of Avraham Avinu is the fact that he treaded the path of Hashem. Ki yidaativ etc. vishomru derech Hashem etc. What is the deeper meaning of this quality of Avraham?
The very desire a person has to emulate the ways of Hashem is mirrored by Hashem's desire to emulate us. When Hashem acts in the manner of midah kineged midah He is in effect mirroring our actions.
In our shabbos davening we say "ki li'olam chasdo" 26 times corresponding to the 26 generations that the world existed based on the chesed of Hashem. At Har Sinai we accepted the Torah and now no longer subsist on chesed but rather earn our keep. That was the quality of Avraham Avinu that characterized his fatherhood of the Jewish people. He desired to go in the derech Hashem emulating Hashem's qualities which is exactly the way Hashem relates to us. He too, starting from matan torah strives [kviyachol] to mimic our behavior [in judging us midah ki'neged middah].
The avoda of "viholachta bidrachav" walking in the ways of Hashem is an avoda of bein adam la-makom even though bein adam la-chaveiro is included as well, as chazal expounded on the pasuk "Just as Hashem is merciful so should you be". Based on the foregoing we understand that they are really two sides of one coin. On one hand bein adam lamakom is included in the bein adam lachaveiro of loving your friend [as we explained that the mitzvah of loving your friend requires reciprocity, that you endeavor to make yourself beloved to your friend as well]. The more one excels at bein adam lamakom [and learns Torah making one a bigger "raya"] the more his friend is obligated to fulfill the bein adam lachaveiro and love him. [ That was "part one".] On the other hand, every bein adam lachaveiro ["just as He is merciful"] is included in the bein adam lamakom of walking in the ways of Hashem [and that was discovered at Matan Torah when Hashem decided that He wants to mimic us with midah kineged midah. That was "part two"].
New light now shines on the mishna that teaches that the world stands on three things "Torah, avoda and gmilus chasodim". These are not 3 distinct categories but rather by the power of Torah, the vessels of avoda [bein adam lamakom] are filled by gmilus chasdim [bein adam lachaveiro]. And the vessels of gmilus chasodim are filled by avoda.