Chapter 18 of the Gospel of Matthew contains the fourth of the five Discourses of Matthew, also called the Discourse on the Church or the ecclesiastical discourse. It compares "the greatest in the Kingdom of Heaven" to a child, and also includes the parables of the lost sheep and the unforgiving servant, the second of which also refers to the Kingdom of Heaven. The general theme of the discourse is the anticipation of a future community of followers, and the role of his apostles in leading it.

Luke 15 is the fifteenth chapter of the Gospel of Luke in the New Testament of the Christian Bible. The book containing this chapter is anonymous, but early Christian tradition uniformly affirmed that Luke the Evangelist composed this Gospel as well as the Acts of the Apostles. This chapter records three parables of Jesus Christ: the lost sheep, the lost coin and the lost or 'prodigal' son, a trilogy about redemption that Jesus tells after the Pharisees and religious leaders accuse him of welcoming and eating with "sinners".