The idea of "justification by faith" is noticeably illustrated in narrative form in the parable of the tax collector and the Pharisee (Luke 18:9-14). Did Luke the evangelist copy or import this idea from the apostle Paul? Or is there a better likelihood that Luke derived the theme from the teachings of Jesus himself? The answers to these questions have implications on the likely origin of this central Christian theme, and the connection between Jesus and Paul. In The Tax Collector and the Pharisee, Peter Tan-Gatue builds a plausible case that this notion of "justification by faith" comes from material sources that already exist in the Jesus tradition. Through biblical exegesis, critical use of authenticity criteria, and contributions in ancient and current historical-cultural studies, this work challenges the idea that justification is a Pauline innovation and also affirms the intrinsic authenticity of the Lukan parable.