Jesus never met a disease he could not cure, a birth defect he could not reverse, a demon he could not exorcise. But he did meet skeptics he could not convince and sinners he could not convert. Forgiveness of sins requires an act of will on the receiver's part, and some who heard Jesus' strongest words about grace and forgiveness turned away unrepentant.
Philip Yancey (2009). “The Jesus I Never Knew Participant's Guide: Six Sessions on the Life of Christ”, p.23, Zondervan