Tanya Chapter 39 part 4

There’s a distinction between the soul that serves and the service that it performs. Depending on the level of intention, the soul’s service of Torah and mitzvot rise to be incorporated within the ten sefirot, the Divine life force, in the higher worlds of either Beriah or Yetzirah. But ultimately, the ten sefirot of the world of Atzilus, which are one with their Emanator, the blessed Infinite One, are within the ten sefirot of every world. The soul, on the other hand, remains in abodes and chambers of the world, as a separate being who delights in the radiance of the Shechina –– which turns out to be the radiance of his or her own Divine acts of Torah and mitzvos which they generated when they served down below in this world.