They shall make for Me a Sanctuary and I shall dwell among them (Exodus 25:8).
The Midrash notes that God did not say, "I shall dwell within it" (the Sanctuary), but "I shall dwell among them" (the Israelites), i.e. the Divine Presence will be within each person.
There are two types of possible relationships. A person may relate to an object, which is a one-way relationship, since the object cannot reciprocate, or a person may react to God and to people, which should be a two-way relationship. Another difference between relating to objects and to beings is that things should be used, whereas God and people should be loved. Unfortunately, the reverse may occur, wherein people fall in love with things but they use God and people. People who behave this way perceive God and people as if they were objects. Inasmuch as the love of oneself is an inevitable fact, love of God and people can occur only when they are permitted to become part of oneself, because then one loves them as one does one's own eyes and ears.
If my relationship to God is limited to going to the Sanctuary and praying for my needs, then I am merely using Him, and God becomes an external object. But when I make His will mine, then His will resides within me and He becomes part of me. This is undoubtedly what the Zohar means by, "Israel, the Torah, and God are one unit," because the Torah, which is the Divine will, is inseparable from God, and when one incorporates the Torah with one's own code of conduct and values, one unites with God.