Jodo Shinshu is the school of the Primal Vow. Everything we do in our religious life must be in accord with the three things mentioned by Amida Buddha in His Primal Vow: “entrust to me, say my Name (Nembutsu) and wish to be born in my land”.
I have already explained in my book The Meaning of Faith and Nembutsu in Jodo Shinshu Buddhism and in my Commentary on the Sutra on the Buddha of Infinite Life