Rabbi Yossi said: Let your fellow's property be as dear to you as your own, prepare yourself to study Torah which is not an inheritance to you, and let all of your deeds be for the sake of heaven.
Rabbi Yose is the Tanna in our Mishnah who said that the good way to which a person should cling to is "a good neighbor" and the bad way which a person should avoid is the "bad neighbor". R. Yose himself certainly followed this philosophy. He tells us in Shabbos 118 that the reason that he lived a long life is because he would never transgress the words of his colleagues. R. Yose was not a Cohen. Yet, even if his colleagues were to tell him to go up and pronounce the Priestly blessings, he would do so. In the merit of his careful cultivation of the trait of congeniality, Rabbi Yose merited that in any dispute between him and one of his friends, the halacha is according to R. Yose (Eruvin 47a).
However, the second teaching of R. Yose is difficult to understand. Why would one think that Torah should come to him by inheritance? After all, there is no branch of knowledge that does not require careful application and many hours of study to master. Furthermore, what does it mean "prepare"? What is this preparation?
I think that R. Yose is teaching us something very important. Do not read, "prepare yourself to study Torah, because it is not an inheritance for you", but read, "prepare yourself to study that Torah which is not an inheritance for you". This reading had the advantage of preserving the tri-partite division of this mishna.
[י [יב] רבי יוסי אומר, יהי ממון חברך חביב עליך כשלך
; התקן עצמך ללמוד תורה שאינה ירושה לך;
וכל מעשיך, יהיו לשם שמיים.
The truth is that someone who grows up in a particular community does, almost by osmosis, receive a certain perspective, a particular approach, a specific sensibility from his community, which can be called an "inheritance". The Torah of Satmar is not the same as that of the Yeshiva World and the Torah of Lubavitch is very different from that of R. Kook, and neither is like the Sephardic tradition. When one seriously engages with another Torah tradition from inside, he often experiences a sense of disorientation in which things are almost the same but not quite the same. One can compare it to the experience of looking into a mirror that is made to distort. One kind of sees the same things, but the inter-relationships and the sense of emphasis and depth perception are very, very different. One does need to "prepare" to make a transition from one tradition to another.
Having done this, however, your actions will be for the sake of heaven. One who knows, understands and values multiple approaches, will not act by habit. He or she will not parrot slogans. A scholar who is proficient in many different pathways of Avoda will know what to do, and more importantly will know what to do for the right reasons.
This does not negate being a good member of the community. R. Yose teaches us that, at the minimum, one must care for one's neighbors money as much as one's own. Rising above parochialism leads one to the level of "for the Sake of Heaven" but the goal always is to remain within a specific community as a way of life as one reaches to Heaven.
Interestingly, ARIZAL in the SEFER DERUSHEI HA'NESHAMOS V'HA'GILGULIM (Perek 3) explains that a person who completed his learning in a prior lifetime only needs, in his present lifetime, to work on the method of learning that he did not yet master. (The words of the Arizal refer to the rest of a person's learning, when he is certain that he is not neglecting to learn basic Halachah; see SHACH YD 246:5.). The mishna then tells one to study Torah which one had not inherited from a previous gilgul.
