Jesus explained that his ministry changed the situation with respect to eating impure animals.
Listen to me, everyone, and understand this. Nothing outside a person can defile them by going into them. Rather, it is what comes out of a person that defiles them.” After he had left the crowd and entered the house, his disciples asked him about this parable. “Are you so dull?” he asked. “Don’t you see that nothing that enters a person from the outside can defile them? For it doesn’t go into their heart but into their stomach, and then out of the body.” (In saying this, Jesus declared all foods clean.) He went on: “What comes out of a person is what defiles them. For it is from within, out of a person’s heart, that evil thoughts come—sexual immorality, theft, murder, adultery, greed, malice, deceit, lewdness, envy, slander, arrogance and folly. All these evils come from inside and defile a person.” ( Mark 7:14-23).When Israel went into the Promised Land, they were relative spirit-free. They needed protection from the evil spirits that filled the land and controlled the Canaanites. The Laws for avoiding impure animals and activities were designed to protect them from picking up evil spirits, but this problem was long gone by Jesus' time.
The children of Israel had rebelled against God and ignored his law. They had chased after sin and lost their spiritual protection. The evil spirits that had filled up the land had taken hold of the children of Israel. The situation was so bad that all the evil spirits in the land had moved to the people who entered the land.
Jesus explained that evil was now at work within them. Avoiding impure foods provided no spiritual protection, because the evil spirits had already moved from the animals and high places into the hearts of the people. Refusing to eat an impure food was pointless, if your heart was full of evil, because you have already given many evil spirits a home there.
The world had changed. Impure animals were no longer a spiritual threat. The real problem was that hundreds of years of rejecting God and pursuing evil had left the Jewish people under the control of the spiritual powers of evil. The spiritual powers of evil knew that something would happen in Jerusalem, so they had concentrated their forces there. The people of evil were controlled and dominated by the forces of evil. This influenced their behaviour. As Jesus said, these evils came out from inside their hearts and defiled their behaviour.
By dying on the cross, Jesus intended to set them free from the spiritual powers of evil that corrupted and crushed their lives. However, the powers of evil stirred them up to reject Jesus and call out for him to be crucified. Most Jews continued to reject Jesus, and their city and country was destroyed in AD 70.
Woe to you, teachers of the law and Pharisees, you hypocrites! You clean the outside of the cup and dish, but inside they are full of greed and self-indulgence. Blind Pharisee! First clean the inside of the cup and dish, and then the outside also will be clean (Matt 23:25-26).In Jesus time, the spiritual threat came from the hearts of the people, because they had allowed the spiritual powers of evil to make their home there. Even the teachers of the law and the Pharisees were corrupted. External evil was no longer a threat, so the laws about impure food were no longer relevant for spiritual protection.