We are not meant to live behind an impenetrable wall. We are supposed to set sparks of holiness in the world but the hard part is not to become influenced by the negative aspects of the world.
We are not of this world but we must live in this world and bring about sparks of holiness to the world to bring about our holy mission to bring Torah and the good news of Yeshua.
When Jacob rebuked Laban for mistreating him and his family, Laban relented and the two made a pact. Jacob erected a stone mound as a monument to their agreement to pass it only to do business, not for hostile purposes.
[Laban said to Jacob,] “I will not cross over to you beyond this mound, and you will not cross over to me beyond this mound and this monument.” Genesis 31:52
As opposed to a solid wall, a mound is a collection of unconnected stones, signifying that the separation between Laban and Jacob would not be absolute.1 Spiritually, this means that Jacob was not erecting an impenetrable barrier between himself and the realm of Laban. He would continue to enter Laban’s realm for the “business” of harnessing the sparks of holiness that reside there, but he would do so while remaining detached from the negative influences of Laban’s philosophy of life.
Similarly, the conceptual “mound” that we must erect to distinguish between ourselves and the mundane world around us must be left semi-permeable. Although we must cross that mound in order to conduct our business of sanctifying the material world, we at the same time must remain immune to its negative aspects.2 1.Likutei Sichot, vol. 5, p. 129. 2. Likutei Sichot, vol. 3, p. 794.