Is it okay for a person who believes in and seeks to obey the Jewish Messiah Jesus to eat pork and shrimp?

Yes. The short answer is that the church has believed it is okay with Jesus no matter what we types of created food we eat. Here was the conclusion of the first church council in their letter to believers among the gentiles:

“We have heard that some went out from us without our authorization and disturbed you, troubling your minds by what they said. It seemed good to the Holy Spirit and to us not to burden you with anything beyond the following requirements: You are to abstain from food sacrificed to idols, from blood, from the meat of strangled animals and from sexual immorality. You will do well to avoid these things. Farewell.” – Acts‬ ‭15‬:‭24‬, ‭28‬-‭29‬ ‭NIV‬‬

Going back to the beginning of humanity, originally, people ate a plant based diet only:

“So God created mankind in his own image, in the image of God he created them; male and female he created them. God blessed them and said to them, “Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish in the sea and the birds in the sky and over every living creature that moves on the ground.” Then God said, “I give you every seed-bearing plant on the face of the whole earth and every tree that has fruit with seed in it. They will be yours for food.” – Genesis‬ ‭1‬:‭27‬-‭29‬ ‭NIV‬‬

However, even then, one certain bit of stubborn vegetation was forbidden:

“The Lord God made all kinds of trees grow out of the ground—trees that were pleasing to the eye and good for food. In the middle of the garden were the tree of life and the tree of the knowledge of good and evil. And the Lord God commanded the man, “You are free to eat from any tree in the garden; but you must not eat from the tree of the knowledge of good and evil, for when you eat from it you will certainly die.”” Genesis‬ ‭2‬:‭9‬, ‭16‬-‭17‬ ‭NIV‬‬

However, people ate from the wrong tree and so life got out of control, even deadly:

“And [the Lord] said, “Who told you that you were naked? Have you eaten from the tree that I commanded you not to eat from?” The man said, “The woman you put here with me—she gave me some fruit from the tree, and I ate it.” … [The Lord said to Adam], “Because you listened to your wife and ate fruit from the tree about which I commanded you, ‘You must not eat from it,’ “Cursed is the ground because of you; through painful toil you will eat food from it all the days of your life. It will produce thorns and thistles for you, and you will eat the plants of the field. By the sweat of your brow you will eat your food until you return to the ground, since from it you were taken; for dust you are and to dust you will return.”” – Genesis‬ ‭3‬:‭11‬-‭12‬, ‭17‬-‭19‬ ‭NIV‬‬

Ten generations later, a global flood wiped out the earth’s creatures. As the Lord was renewing the earth, He allowed people to eat meat … again, with certain restrictions:

“Then God blessed Noah and his sons, saying to them, “Be fruitful and increase in number and fill the earth. The fear and dread of you will fall on all the beasts of the earth, and on all the birds in the sky, on every creature that moves along the ground, and on all the fish in the sea; they are given into your hands. Everything that lives and moves about will be food for you. Just as I gave you the green plants, I now give you everything. “But you must not eat meat that has its lifeblood still in it. And for your lifeblood I will surely demand an accounting. I will demand an accounting from every animal. And from each human being, too, I will demand an accounting for the life of another human being.” – Genesis‬ ‭9‬:‭1‬-‭5‬ ‭NIV‬‬

Later, the Lord reinforced and clarified the reason for the restriction against consumption of blood: life is in the blood and sin would be atoned for and forgiven through the offering of blood:

“For the life of a creature is in the blood, and I have given it to you to make atonement for yourselves on the altar; it is the blood that makes atonement for one’s life. Therefore I say to the Israelites, “None of you may eat blood, nor may any foreigner residing among you eat blood.” Any Israelite or any foreigner residing among you who hunts any animal or bird that may be eaten must drain out the blood and cover it with earth, because the life of every creature is its blood. That is why I have said to the Israelites, “You must not eat the blood of any creature, because the life of every creature is its blood; anyone who eats it must be cut off.” … Anyone, whether native-born or foreigner, who eats anything found dead or torn by wild animals must wash their clothes and bathe with water, and they will be ceremonially unclean till evening; then they will be clean.” – Leviticus‬ ‭17‬:‭11‬-‭15‬ ‭NIV‬‬

After this, the Lord clarified for Israel what foods were acceptable and which ones weren’t. These rules became the basis for Kosher laws:

“You may eat any animal that has a divided hoof and that chews the cud. Of all the creatures living in the water, you may eat any that has fins and scales. But any winged creature that is clean you may eat. Do not eat anything you find already dead. You may give it to the foreigner residing in any of your towns, and they may eat it, or you may sell it to any other foreigner. But you are a people holy to the Lord your God. Do not cook a young goat in its mother’s milk.” – Deuteronomy‬ ‭14‬:‭6‬, ‭9‬, ‭20‬-‭21‬ ‭NIV‬‬

Some of these rules don’t make sense now, but the likely were intended to keep Israel out of pagan rituals and unhealthy practices. Even today, militaries teach similar principles for survival: for example: don’t eat carnivorous animals or animals found dead.

However, there was a promise that God would provide for the daily needs of those who trusted in the Lord:

“This poor man called, and the Lord heard him; he saved him out of all his troubles. … Taste and see that the Lord is good; blessed is the one who takes refuge in him. … The lions may grow weak and hungry, but those who seek the Lord lack no good thing.” – Psalms‬ ‭34‬:‭6‬, ‭8‬, ‭10‬ ‭NIV‬‬

Indeed, it seems that the enjoyment of these daily gifts of food were designed by God to lend happiness to our lives, when enjoyed rightly:

“I know that there is nothing better for people than to be happy and to do good while they live. That each of them may eat and drink, and find satisfaction in all their toil—this is the gift of God. … Be warned, my son, of anything in addition to them. Of making many books there is no end, and much study wearies the body. Now all has been heard; here is the conclusion of the matter: Fear God and keep his commandments, for this is the duty of all mankind. For God will bring every deed into judgment, including every hidden thing, whether it is good or evil.” – Ecclesiastes‬ ‭3:12-13; 12‬:‭12‬-‭14‬ ‭NIV‬‬

However, by the time of Jesus, man-made rules for food and sharing meals had become complicated and burdensome … so much so that people were neglecting the more important matters of keeping a clean heart and truly holy life:

“The Pharisees and some of the teachers of the law who had come from Jerusalem gathered around Jesus and saw some of his disciples eating food with hands that were defiled, that is, unwashed. (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.) So the Pharisees and teachers of the law asked Jesus, “Why don’t your disciples live according to the tradition of the elders instead of eating their food with defiled hands?” He replied, “Isaiah was right when he prophesied about you hypocrites; as it is written: “ ‘These people honor me with their lips, but their hearts are far from me. They worship me in vain; their teachings are merely human rules.’ Again Jesus called the crowd to him and said, “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 ‭7‬:‭1‬-‭7‬, ‭14‬-‭15‬, ‭17‬-‭23‬ ‭NIV‬‬

Apparently, it took a while for Peter and the other missionaries to grasp the implications of this, but the Lord did get the message through in a dramatic way:

“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. 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. They called out, asking if Simon who was known as Peter was staying there. While Peter was still thinking about the vision, the Spirit said to him, “Simon, three men are looking for you. So get up and go downstairs. Do not hesitate to go with them, for I have sent them.” As Peter entered the house, Cornelius met him and fell at his feet in reverence. But Peter made him get up. “Stand up,” he said, “I am only a man myself.” 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.” – Acts‬ ‭10‬:‭9‬-‭20‬, ‭25‬-‭28‬ ‭NIV‬‬

God wanted people from every culture to have access to the forgiveness that is in Christ, and the church realized that extra food laws for the gentile believers, were unnecessary. They returned to the basic guidelines God had given in Noah’s time:

“When they finished, James spoke up. “Brothers,” he said, “listen to me. “It is my judgment, therefore, that we should not make it difficult for the Gentiles who are turning to God.” – Acts‬ ‭15‬:‭13‬, ‭19‬ ‭NIV‬‬

Today, people who believe in Jesus as Lord follow a wide variety of dietary patterns, some choices are based on religious principles, some on health or allergy concerns, and sometimes we adapt our diet based on not wanting to offend others:

“Accept the one whose faith is weak, without quarreling over disputable matters. One person’s faith allows them to eat anything, but another, whose faith is weak, eats only vegetables. The one who eats everything must not treat with contempt the one who does not, and the one who does not eat everything must not judge the one who does, for God has accepted them. … Therefore let us stop passing judgment on one another. Instead, make up your mind not to put any stumbling block or obstacle in the way of a brother or sister. I am convinced, being fully persuaded in the Lord Jesus, that nothing is unclean in itself. But if anyone regards something as unclean, then for that person it is unclean. If your brother or sister is distressed because of what you eat, you are no longer acting in love. Do not by your eating destroy someone for whom Christ died. Therefore do not let what you know is good be spoken of as evil. For the kingdom of God is not a matter of eating and drinking, but of righteousness, peace and joy in the Holy Spirit, because anyone who serves Christ in this way is pleasing to God and receives human approval.” – Romans‬ ‭14‬:‭1‬-‭3‬, ‭13‬-‭18‬ ‭NIV‬‬

Since life is about more than food, we should walk in the Holy Spirit and relate to one another in a rightly considerate, peaceful, and joyful way, all for God’s glory:

“The earth is the Lord’s, and everything in it.” So whether you eat or drink or whatever you do, do it all for the glory of God. – 1 Corinthians‬ ‭10‬:‭26‬, ‭31‬ ‭NIV‬‬

One day, the Lord will have a feast for all who are trusting Him faithfully and we will be totally and perfectly satisfied in the presence of God forever:

“Then the angel showed me the river of the water of life, as clear as crystal, flowing from the throne of God and of the Lamb down the middle of the great street of the city. On each side of the river stood the tree of life, bearing twelve crops of fruit, yielding its fruit every month. And the leaves of the tree are for the healing of the nations. No longer will there be any curse. … Blessed are those who wash their robes, that they may have the right to the tree of life and may go through the gates into the city. Outside are the dogs, those who practice magic arts, the sexually immoral, the murderers, the idolaters and everyone who loves and practices falsehood. … The Spirit and the bride say, “Come!” And let the one who hears say, “Come!” Let the one who is thirsty come; and let the one who wishes take the free gift of the water of life. … The grace of the Lord Jesus be with God’s people. Amen.”

‭‭Revelation‬ ‭22‬:‭1‬-‭3‬a, 14‬-‭15‬, ‭17‬, ‭21‬ ‭NIV‬‬

God’s eternal favor, that’s the bottom line!!