The following is an excerpt from The MacArthur New Testament Commentary on Luke 7.

The main thrust of this passage appears on the surface to be the transformed life of the sinful woman. But she was merely one element of the story, which focuses primarily on the Lord evangelizing a Pharisee. Jesus used her as a testimony to him and the others present of the truth and power of the gospel. Ironically, Jesus demonstrated His power to forgive sins and transform lives by using the very type of person the Pharisees despised the most. In reality, the self-righteous, hypocritical religious leaders were the worst possible sinners; people who believe they are not lost and think they do not need redemption cannot be saved.

The Lord Jesus Christ came to seek and save the penitent and believing lost (Luke 19:10)—the self-righteous members of the religious establishment as well as the outcast riff raff of society

As the story opens, one of the Pharisees was requesting the Lord to dine with him. Like the other Pharisees who invited Jesus to a meal, this Pharisee had no personal interest in Him. He was not an open-minded inquirer, but had like the majority of the Pharisees, already decided that Jesus was a blasphemer, arrogating to Himself the right to forgive sins that belongs to God alone (Luke 5:21).These self-appointed guardians of legalistic, external, ritualistic religion hated Jesus’ message of grace, repentance, and forgiveness, and His call for sincere love of God from the heart. They also hated Him for pointedly rebuking their hypocritical self-righteousness (Matt.23),and for associating with the outcasts of society (Luke 7:34). Having already reached a conclusion regarding Jesus, they were busy accumulating evidence against Him. This Pharisee’s invitation to Jesus was part of that evidence-gathering process. No self-respecting Pharisee would invite any association with a blasphemer, except to do him harm.

After finishing washing them, the woman began kissing Jesus’ feet. Kissing is an intense word. In Luke 15:20 it describes the father’s kissing of the prodigal son on his return home. Luke used it in Acts 20:37 to describe how the elders of the church at Ephesus kissed Paul when he took his leave of them. The woman’s kissing of Jesus’ feet was a striking expression of affection. Then, unwilling or unable to wait any longer, she did what she had come to do and anointed the Lord’s feet with the perfume. This was a staggering display of honor rendered to Jesus in the midst of those who sought only to dishonor Him.

The woman’s actions could have put Jesus in a very bad light. After all, she was a notorious sinner. Letting down her hair, washing, kissing, embracing, and anointing His feet was a serious breach of propriety. That may have led some to wonder why she felt the freedom to be so familiar with Him and reach an obvious, but wrong, conclusion. The Lord’s sinless, unblemished character (John 8:46) precluded any thoughts of impropriety on His part, even on the part of His enemies.

The Pharisee drew an equally false conclusion: he chalked up the Lord’s reaction not to evil, but to ignorance. That, however, was proof to him that Jesus could not be who He claimed to be because, the Pharisee reasoned, “If this man were a prophet He would know who and what sort of person this woman is who is touching Him, that she is a sinner.” How could Jesus tell them things they did not know if He did not even know what they themselves knew about this woman? After all no sensible religious teacher, let alone one claiming to be the Messiah, would ever allow such a woman to touch Him. The Pharisee was both disgusted by the scene he was witnessing, and at the same time satisfied, because it confirmed his belief that Jesus’ ignorance of this woman’s wickedness was proof that He was not a true prophet.