Some Christians eat Pork. Some Christians like me don't. You may ask why do I obey dietary laws? Let me state my reasons.
Malachi 3:6 - "I the Lord do not change."
Hebrews 13:8 - "Jesus is the same yesterday and today and forever."
We see Jesus Christ saying this in John 10:30 - "I and the Father are one."
Since Father and Son are one, we know that the son Jesus Christ cannot reject the teachings of his Father God.
Also remember what Jesus said in Matthew 5:17 - "Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them."
But you may ask what about Mark chapter 7:18 where Jesus says "Don’t you see that nothing that enters a person from the outside can defile them?"
We have to notice one major thing while we read this. Jesus Christ said this to the Pharisee Jews and other Jewish teachers of the law. Not to the Gentiles.
On the top of this, Jesus was a Jew and he didn't break a single commandment of Torah.
This is what Jesus said to Jews - Whatever they eat goes into their stomach and then out of the body. But what comes out of them is what defiles them, because it comes from their hearts. Not from their stomachs.
We read this in Mark 7:21-23 - "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.”
In Mark 7:3-4 - "The Pharisees and all the Jews do not eat unless they give their hands a ceremonial washing, holding to the tradition of the elders. When they come from the marketplace they do not eat unless they wash. And they observe many other traditions, such as the washing of cups, pitchers and kettles."
We read that Pharisees and other Jews favored the tradition of elders over Torah. Through favoring their traditions of the elders, they have set aside the commands of God.
In Mark 7:8-9, Jesus says this.
Mark 7:8-9 - "You have let go of the commands of God and are holding on to human traditions. And he continued, “You have a fine way of setting aside the commands of God in order to observe your own traditions!"
Through their so called traditions, Pharisees and other Jews tried to make themselves very clean "outwardly". But through "inwardly", they have defiled themselves through their evil natures - adultery, murder, theft, fornication, etc.
Remember that, the generation of Jews during the time of Jesus was extremely evil.
We see Jesus calling them "wicked (or sinful) and adulterous generation." (Matthew 12:39, Matthew 16:4, Mark 8:38, etc.). We also see Jesus calling people in that generation that their father is devil (John 8:44) due to their evil nature. We also see Both Jesus Christ and John the Baptist calling them "offspring of vipers" (Matthew 23, Luke 3).
Even Jewish Priest Josephus agrees with Jesus on the wickedness of that generation.
"I shall therefore speak my mind here at once briefly: — that neither did any other city suffer such miseries, nor did any age ever breed a generation more fruitful in wickedness than this was, from the beginning of the world." (Jewish Wars V, 10:5).
In Mark 7:6-7, we see Jesus Christ mentioning Prophet Isaiah and his prophesy when he tells this to Pharisees and teachers of the law.
It must be noted that we read this in Isaiah 66:17 - “Those who consecrate and purify themselves to go into the gardens, following one who is among those who eat the flesh of pigs, rats and other unclean things—they will meet their end together with the one they follow,” declares the Lord."
But you may ask what about Peter's vision in Acts Chapter 10?
Acts 10:9-16 – “About noon the following day as they were on their journey and approaching the city, Peter went up on the roof to pray. He became hungry and wanted something to eat, and while the meal was being prepared, he fell into a trance. He saw heaven opened and something like a large sheet being let down to earth by its four corners. It contained all kinds of four-footed animals, as well as reptiles and birds. Then a voice told him, “Get up, Peter. Kill and eat.” “Surely not, Lord!” Peter replied. “I have never eaten anything impure or unclean.” The voice spoke to him a second time, “Do not call anything impure that God has made clean.” This happened three times, and immediately the sheet was taken back to heaven.”
When it comes to a vision or a dream, We should not take them literally. This is because it can have figurative or symbolic meanings.
Let me take an example from Genesis Chapter 41. When Pharaoh saw the dreams in his sleep, he knew these dreams should not be taken literally. He knew these dreams had a figurative or a symbolic meaning. That's why he called in Magicians and Wise Men of Egypt to interpret the dreams. Later, we see Pharaoh calling for Joseph to interpret the dreams when others failed to interpret them.
We see Joseph interpreting the dreams to Pharaoh in Genesis 41:25-27 (NIV) "Then Joseph said to Pharaoh, “The dreams of Pharaoh are one and the same. God has revealed to Pharaoh what he is about to do. The seven good cows are seven years, and the seven good heads of grain are seven years; it is one and the same dream. The seven lean, ugly cows that came up afterward are seven years, and so are the seven worthless heads of grain scorched by the east wind: They are seven years of famine."
Through this, we learn that a dream or a vision can have symbolic or figurative meanings.
Acts 10:17 - "While Peter was wondering about the meaning of the vision, the men sent by Cornelius found out where Simon’s house was and stopped at the gate."
So we see that Peter was wondering about what the vision really meant instead of taking it literally.
The meaning of Peter's vision is that Peter should not call Gentiles as unclean or impure.
We understand the meaning of Peter's vision in Acts 10:27-28.
In Acts 10:27-28 - "While talking with him, Peter went inside and found a large gathering of people. He said to them: “You are well aware that it is against our law for a Jew to associate with or visit a Gentile. But God has shown me that I should not call anyone impure or unclean."
Through Jesus Christ, the salvation is also open to Gentiles. So Peter’s vision in Acts 10 has nothing to do with God’s dietary laws.
So I believe it is absolutely necessary for the Christians to keep the dietary laws.