Krishna now reveals the reward. Those who take refuge in this knowledge attain His own nature. They are not born again when a new creation cycle begins, and they are not troubled when everything dissolves at the end of a cycle.
Consider a child who has learned to swim. Once that skill is truly theirs, water holds no fear for them. In the same way, a person who has internalized this knowledge of the gunas is no longer tossed about by the cycle of birth and death. The cycle continues, but it no longer has a grip on them.
The word "sadharmya" means sharing the same dharma or nature. Those established in this knowledge take on qualities similar to Krishna's own: peace, bliss, and imperishability.