The permanent state of which you speak cannot be permanent, within a physical body. You can have realizations with states of consciousness but that is what they are, not states of being.
For example, you can witness the state of “non thinking” in deep meditation, but you are the witness, not the state.
On Enlightenment you go to that “permanent state” for a while, you feel different and life should change for you – but you come back to live your life, albeit from a different perspective. I repeat, you DO come back, you have to, or you could not function as a human being.
When an Enlightened person dies they shed first their physical shell, ascend to the higher dimensions and enter into a”big sleep” continuing to shed further bodies that were used while in human form on Earth. Then a shift occurs and “they” are no longer the “individual” but still conscious, a Being of Light. The Being of Light then joins with their Essence which permanently resides in the Spiritual Worlds..
Following this there are 3 possibilities:
1. Merging into the Oneness…….forever.
2. Staying in the Spiritual Worlds, serving and continuing to learn.
3. Returning to the physical dimensions by taking another set of vehicles to further pursue life’s lessons.