Mark 7:18. “ “And he said to them, “Then are you also without understanding? Do you not see that whatever goes into a person from outside cannot defile him,”
IF Jesus had declared the distinction of clean and unclean foods were over, Peter would not have reacted the way he did in Acts 10:9 - 18, Acts 11:5 - 18 where Peter had to overcome his phobia of Gentiles as an unclean race to dismiss as unclean. Peter well understood not to eat unclean foods as did all Jews.
Lastly remember the reason we all die? Lust for an apple in the Garden of Eden. We have to control our appetites for only clean things. God has rules.
Does God (of both the Old Testament and the New Testament) think that if a drunkard drinks a half-gallon of cheap whiskey from outside, that will not be unhealthy for him?Of course not! God is not stupid! Every single one of those things going "into a person from outside" is VERY unhealthy for them, and God knows that perfectly well.
Does God think that if a person ingests a spoonful of arsenic from outside, that will not be "unhealthy" for him?
Does God think that if a person ingests a spoonful of tetrodotoxin from outside, that will not be "unhealthy" for him?
Does God think that if a person ingests a spoonful of cyanide from outside, that will not be "unhealthy" for him?
Does God think that if a person ingests a spoonful of strychnine from outside, that will not be "unhealthy" for him?
Does God think that if a person ingests a spoonful of ricin from outside, that will not be "unhealthy" for him?