But when the king came in to look at the guests, he saw there a man who had no wedding garment. And he said to him, ‘Friend, how did you get in here without a wedding garment?’ And he was speechless. Then the king said to the attendants, ‘Bind him hand and foot and cast him into the outer darkness. In that place there will be weeping and gnashing of teeth.’ For many are called, but few are chosen.” (Matthew 22:11-14)
Jesus spoke the parable of the wedding feast to the Pharisees, the rulers of the Jewish people in His day. With this parable, He told them that because they have rejected Him, they have rejected the Kingdom of God. From now on, the Lord will open His Kingdom to all those the Jews tried to keep out: the pagans, the Gentiles, and those the Jews considered sinners. The Lord will offer all these His grace and mercy. But though the Lord invites all to come to His wedding feast, this is not an offer of cheap grace.
The Kingdom of Heaven may be a joyous celebration but, as the example of the treatment of the man who was not properly clothed shows us, no one can come into that Kingdom as they are, with all their sins or their own righteousness or even their own religious beliefs or practices. Many in our world today claim that God will accept you as you are, but that is not what Jesus is saying here at all.
What Jesus tells us is that, although the Lord desires to call all unto Himself, only those who are clothed with the righteousness of Christ can enter His Kingdom, no matter how good, noble or popular they are. This is very difficult for many people to accept in our present day considering the popular view that most people go to heaven (or its equivalent) regardless of their religious beliefs or moral character. In the world, moral character is not determined these days by referring to Biblical standards or even the 10 commandments. Goodness is not determined by what is popular or how nice a person is, or how generous and friendly, nor is it a popularity contest. As Jesus says, we must be clothed in His righteousness, not our own. This is granted only by faith which reveals to us our utter sinfulness and our need for a Savior.