“When the unclean spirit has gone out of a person, it passes through waterless places seeking rest, but finds none. Then it says, ‘I will return to my house from which I came.’ And when it comes, it finds the house empty, swept, and put in order. Then it goes and brings with it seven other spirits more evil than itself, and they enter and dwell there, and the last state of that person is worse than the first. So also will it be with this evil generation.” — Matthew 12:43-45
“The Pharisees were classic moralists. There was no other group in existence at the time that was more committed to ethics, standards, principles of life, and morals than the Pharisees. They lived by a complex and demanding ethical moral code. Laws existed for everything, and their life was utterly and totally circumscribed by a mass of legislation and morality. In some ways, they would be the moral majority of their time; they were calling people to ethical behavior based upon the law of their own pious tradition. But in the process of their moral pursuit, they were in fact rejecting God Himself, who was in their midst in human form.
So while they were deeply entrenched in morality, they were damned to Hell. It appears as though the more they came to commit themselves to morality, the more they set in concrete their own judgment. They cleaned up their lives outwardly, and so effectively did they do this that they convinced themselves that they were righteous, moral, and good. Consequently, when someone came along preaching the message of sin, they were not interested in listening.
So under the illusion of their own self-righteousness, they became unreachable. Jesus had little trouble reaching the harlots, the thieves, robbers, criminals, outcasts, and sinners of society, including the tax collectors and the extortionists, but He had an almost impossible time reaching the religious, self-righteous, moral people who were under the illusion and self-deception that because of their goodness, everything was OK between them and God. They recognized no sin, so they needed no Savior.
That is always the danger of morality. Morality creates an illusion of safety when in fact the person who is moral may be in the greatest danger of all. We see this particularly among the Mormons, who feel so secure because of their morality when in fact, they are so insecure and under the judgment of God and so hard to convince.”
– John MacArthur
taken from: Reformation vs. Relationship, sermon from Matthew 12:43-50 (Grace to You)