The Paramatma is beginningless — it has no origin point. It is beyond all three gunas. It is imperishable. And even though it resides inside this body, it neither performs any action nor gets stained by any action's result.
A lotus flower lives in water but is never soaked by it. In just that way, the Supreme Self lives within the body yet remains untouched by the body's deeds, its pleasures, its sorrows. This is its fundamental nature.