In the Mahayana, the "Great Vehicle" of Buddhism, the Buddha teaches that the end of suffering, the Nirvana that we obtain following the path of the Small Vehicle, is not yet the full Enlightenment.
The Mahayana's practitioner, aiming not only at his own liberation but at the liberation of all sentient beings, through the development ofBodhicitta (the Spirit of Enlightenment, which consists of Love/Compassion that doesn’t cling to the peace of Nirvana, and Wisdom that is not caught up by the confusion of Samsara ), follows the Bodhisattva’s path, searching for full Enlightenment in order to be able to help all sentient beings.
This is realized through the accumulation of Merit and Wisdom, practicing the Six Paramitas, the Six Perfections: Generosity, Morality, Patience, Zeal, Meditative Absorption and Wisdom. In this way, it is said that a Bodhisattva, (a Hero of the Spirit of Enlightenment), in a journey that may last countless lives, walks through the five paths and the ten levels of Enlightenment, purifying all the veils that still cover his Buddha Nature, and reaches the complete purity and maturity of a fully perfect Buddha.
The essence of this journey is to take onto ourselves the burden of all sentient beings’ pains giving them all the happiness and merits we are able to give. From then on, he manifests an infinite and spontaneous enlightened activity for the sake of all sentient beings that lasts as long as Samsara exists.