clean and unclean

I've heard people talk about 'things unclean' like certain animals and such. This was stated in the old testament but Jesus came and declared all food clean. Mark7:14 says:
¹⁴ Again Jesus called the crowd to him and said, “Listen to me, everyone, and understand this. ¹⁵ Nothing outside a person can defile them by going into them. Rather, it is what comes out of a person that defiles them.” ^[16] ^f]">[f]

¹⁷ After he had left the crowd and entered the house, his disciples asked him about this parable. ¹⁸ “Are you so dull?” he asked. “Don’t you see that nothing that enters a person from the outside can defile them? ¹⁹ 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.)

²⁰ He went on: “What comes out of a person is what defiles them. ²¹ For it is from within, out of a person’s heart, that evil thoughts come—sexual immorality, theft, murder, ²² adultery, greed, malice, deceit, lewdness, envy, slander, arrogance and folly. ²³ All these evils come from inside and defile a person.”

defile and unclean are used interchangeably comparing bibles.

So it is not the food we eat that makes us unclean but the evil (sin) we keep in our hearts. This is why we must confess our sins and do our best to be better people. God put all good food for us to make and use.

Romans 14:17

¹⁷ For the kingdom of God is not a matter of eating and drinking, but of righteousness, peace and joy in the Holy Spirit, ¹⁸ because anyone who serves Christ in this way is pleasing to God ...