When Jesus spoke the parable of the Two Sons in Matthew 21:28-32, he wasn’t telling a story about always following through on what you say, or how to show proper respect to your parents. The parable tells of one of the sons, who, when asked by his afther to go out and work in the vineyard, said ‘yes’ but did not go and the other son, who said ‘no, he would not go’ but then did go.  The point that Jesus was making is that there are plenty who will gladly say ‘yes’ to God but their ‘yes’ amounts to nothing. The Pharisees were men like that. They said ‘yes’ on the outside, but inwardly their hearts were far from Him. They were hypocrites. The only cure for hypocrisy is repentance,  shown to us by the second son who turned away (repented) from his selfish ways. Entry to the Kingdom of God is clearly marked ‘for the repentant’. No-one else but they will come in. This is why Jesus told the Pharisees that ‘tax-collectors and prostitutes’ will enter the Kingdom of God. It is because repentance leads to salvation.