Everything is pure for someone whose heart is pure. But nothing is pure for an unbeliever with a dirty mind. That person's mind and conscience are destroyed.
Then Haggai said, “Suppose someone has touched a dead body and is considered unacceptable to worship God. If that person touches these foods, would they become unclean?” “Of course they would,” the priests answered.
The Lord Jesus has made it clear to me that God considers all foods fit to eat. But if you think some foods are unfit to eat, then for you they are not fit.
But if you do have doubts about what you eat, you are going against your beliefs. And you know that is wrong, because anything you do against your beliefs is sin.
Not everyone knows these things. In fact, many people have grown up with the belief that idols have life in them. So when they eat meat offered to idols, they are bothered by a weak conscience.
So let's come near God with pure hearts and a confidence that comes from having faith. Let's keep our hearts pure, our consciences free from evil, and our bodies washed with clean water.
But Christ was sinless, and he offered himself as an eternal and spiritual sacrifice to God. That's why his blood is much more powerful and makes our consciences clear. Now we can serve the living God and no longer do things that lead to death.