Can all sentient beings be fully liberated?

One tathāgatagarbha corresponds to one sentient being and gives birth to one sentient being; therefore the tathāgatagarbha is also called the realm of sentient beings. The Heart Sutra says that the tathāgatagarbha neither arises nor ceases, and the realm of sentient beings neither increases nor decreases. Neither increasing nor decreasing means it does not mutate; neither arising nor ceasing means it never needs to arise and can never cease. Therefore, the number of tathāgatagarbhas is forever fixed and unchanging, and they are inexhaustibly numerous. Because there are so many sentient beings and so many tathāgatagarbhas, they cannot be counted clearly, and so they are said to be immeasurable in number.

With so many tathāgatagarbhas corresponding to so many sentient beings, can all sentient beings be liberated in the end? As long as the realm of sentient beings no longer increases and Buddhas and Bodhisattvas become ever more numerous, all sentient beings will sooner or later be liberated. No matter how many there are, there will come a day when they are all liberated; it is only that the time is undetermined—infinitely long, unspeakably and indescribably long. When all sentient beings have become Buddhas, there will be no sentient beings left to liberate, and the abiding of the Buddhas in the world will no longer be necessary or meaningful; they should all go to nirvāṇa. The Buddhas have no need to seek trouble when there is none, and the worlds of the ten directions will likewise have no reason to exist. For those sentient beings who become Buddhas last, cultivation will be extremely effortless—one Buddha protecting and supporting one sentient being—so that their cultivation will be like riding a rocket. This final batch of sentient beings will never again have the opportunity to create unwholesome karma; the seeds of ignorance and karma will be eliminated extremely quickly, and they will be able to attain buddhahood without having to liberate sentient beings, because once ignorance is gone, they have already become Buddhas.