To understand what it means to let the heart be whole, an analogy is called for.
Think of physics. The physicist used to know more or less everything about his subject, but now his discipline has many branches.
Once a builder had enough skill to cope with the whole job; today he needs an array of tradesmen.
In religion too, the old-time Jew was a Jack of all trades. He went to synagogue to pray, to learn, to give tz’dakah. The smallest community had a Chevra Shass or Chevra T’hillim; the poorest house had an array of charity pushkes.
A Jew wore tzitzit, put on tefillin, bensched after meals. On Shabbat he was a king and his wife was a queen; the children were princes and princesses. In business all was honest and above board. At night one could face God and one’s conscience.
These were all-round Jews; their hearts were whole with the Lord their God.
Today many lead a fragmented Jewish life. We support the synagogue but don’t pray, establish schools but don’t study, give to the Holy Land but don’t think of living there.
We daven without understanding, refrain from food but speak lashon ha-ra on Yom Kippur, eat matzah on Pesach but ignore those who eat the bread of affliction all the year.
We are Bar-Mitzvah, cemetery, food or humour Jews.
We think because in other areas the Jack of all trades is outmoded, it is like that in Jewish life too. As a result, Judaism suffers; we all suffer, because we miss the full richness of the Jewish experience.
In Judaism you can have your own emphases, but you have to be a Jack (or Ya’akov) of all trades.