Theravada practitioners aim to free only themselves from samsara, while the bodhisattvas aspire to do that for themselves and all other sentient beings. Frankly, to single-handedly lead all sentient beings to liberation is an extremely difficult task, one that not even the Buddha could have accomplished in a single lifetime. But the infinite power and aspiration of the Buddha have continued to benefit all those who are receptive to his teachings until this day. Even so, he cannot deliver all sentient beings. What matters is not that everyone can be saved but that we all strive toward that worthy end.

- Quote from The Right View, "The Four Noble Truths—the Path Out of Samsara"