The Primal Vow: Liberation of All Sentient Beings

In 18th Vow, Dharmakara vowed:
"If, when I attain Buddhahood, sentient beings in the lands of the ten quarters who sincerely and joyfully entrust themselves to me, desire to be born in my land, and call my Name, even ten times, should not be born there, may I not attain perfect Enlightenment. Excluded, however, are those who commit the five gravest offenses and abuse the right Dharma." - http://www.onmarkproductions.com/html/48-bosatsu-vows.shtml

Of those sentient beings who commit the five gravest offenses and abuse the right Dharma, Shinran wrote that when they repent of their transgressions, they step crosswise from the path to hell onto the path to the Pure Land.

All it takes is the willingness to admit to their mistakes, make amends and change their ways.

According to Kyo Gyo Shin Sho (KGSS) 6: 75 - http://www.shinranworks.com/majorexpositions/kgssVI-73_80.htm
Shinran did not object to uttering the Nembutsu out of repentance for committing one of the five gravest offenses.

The five gravest offenses consist of "Killing father, mother, monk, injuring the Buddha, and creating schisms in the Sangha (Hinayana Buddhism); vandalizing temples, statues, and scriptures, slandering the teaching, obstructing religious practices, violating the five precepts and committing ten evils (Mahayana Buddhism)." - http://www.livingdharma.org/Tannisho/TannishoGlossary.html

Regarding abuse of the right Dharma, in KGSS 6:80 Shinran states:
"there is no dharma that can be abused, for the right dharma cannot be practiced in the latter part of the semblance dharma-age and in the last dharma-age. What is there that can be called abuse of the dharma? There are no precepts to be broken. Who is there that can be called one who breaks precepts?"

Shinran wrote the above as part of the response to the question, "how do we know that the Nirvana Sutra and the other sutras prohibit breaking precepts during the right dharma-age and that this does not apply to monks of the semblance and last dharma-ages?"

Thus the exception becomes null and void in the real world.

All sentient beings "who sincerely and joyfully entrust themselves to me (Amida), desire to be born in my (Amida's) land, and call my (Amida's) Name, even ten times" are to be reborn in the Pure Land of Bliss.

First this occurs as the belief that the Pure Land is right here in the Shin Buddhist's heart-mind.

With faith that the Pure Land practitioner will be reborn in the Pure Land comes the faith that Amida and His Pure Land are right here, right now in his heart.

In saying the Nembutsu sincerely and joyfully with single-minded devotion, be it once or even ten times, the Shin Buddhist turns belief in the Pure Land into faith in the Pure Land.

Thus by such practice, the Pure Land practitioner puts trust in Amida, out of desire to be born in His land.

In this way does the Primal Vow liberate all sentient beings.