There are two paths by which Bodhisattvas reach the stage of non-retrogression: the path of difficult practice and the path of easy practice.
The path of difficult practice is attempting to reach the stage of non-retrogression through self-effort in the age of the five corruptions, when no Buddha dwells in the world. […] The path of difficult practice is, therefore, like an overland journey, painstakingly made on foot.
The path of easy practice is aspiring to be born in the Pure Land through faith in Amideva and attaining birth by the power of His Vows. In the Pure Land, we are sustained by the Buddha’s power and join those who are rightly established in the Mahayana path. […] The path of easy practice is, therefore, like a pleasant journey on water, serenely made by boat.