Summary: Is vegetarianism (or the related practice of veganism) the biblically encouraged choice for Christians? It appears not. Jesus ate both meat and fish, and the apostle Paul called the vegetarian Christian's faith "weak."
Some Christians are vegetarians or vegans. Most are not. Some have chosen a vegetarian or vegan diet for nonreligious reasons, including personal beliefs about nutrition and diet. It is not my intent today to address those nonbiblical issues, which can be controversial and sometimes lead to heated discussions. I leave those conclusions to your own wisdom and discretion.
My purpose in this brief bible study is to show from the New Testament that there are no biblical reasons that direct a Christian to choose a vegetarian or vegan lifestyle. If a Christian chooses veganism or vegetarianism for other, non-biblical reasons, that is certainly his or her prerogative. But the bible itself does not promote that choice. Let's look at some Scriptures.
Mark 14:12-14 On the first day of the Feast of Unleavened Bread, when it was customary to sacrifice the Passover lamb, Jesus’ disciples asked him, “Where do you want us to go and make preparations for you [Jesus] to eat the Passover?”  So he sent two of his disciples, telling them, “Go into the city, and a man carrying a jar of water will meet you. Follow him.  Say to the owner of the house he enters, ‘The Teacher asks: Where is my guest room, where I [Jesus] may eat the Passover with my disciples?’ "
•• Jesus ate the Passover lamb. It is beyond dispute that the Lord Himself was a meat eater. And His twelve apostles ate the lamb with him.
•• That to me personally is sufficient reason, without need of further proof, that it is entirely appropriate for Christians to eat meat.
•• Jesus was quite well aware that eating meat of necessity involved the killing of animals. Nevertheless He continued to eat meat with no indicated hesitation. Those who encourage Christians not to eat meat out of compassion for the animals are adopting for themselves moral scruples that were evidently not shared by the Son of God Himself on this issue.
Luke 24:42-43 They gave [Jesus] a piece of broiled fish, and he took it and ate it in their presence.
John 21:9-10, 12-13, KJV As soon then as they were come to land, they saw a fire of coals there, and fish laid thereon, and bread.  Jesus saith unto them, Bring of the fish which ye have now caught...  Jesus saith unto them, Come and dine. And none of the disciples durst ask him, Who art thou? knowing that it was the Lord.  Jesus then cometh, and taketh bread, and giveth them, and fish likewise.
•• We have already seen that Jesus ate meat. Here we see that Jesus also ate fish, and He gave fish also to His disciples to eat.
•• The eating of fish was given further approval by Jesus in His miraculous feeding of the 5,000 (Luke 9:13-17) and the 4,000 (Mark 8:6-9) with bread and fish.
•• As we saw with Jesus eating meat, we likewise do not see Him showing any moral hesitation about the taking of the lives of fish in order to eat them. Christian vegans and vegetarians may indeed have such scruples, and that is their free choice. But again, those were not moral scruples shared by Jesus Christ, as is evidenced by His having eaten both meat and fish.
Acts 11:5-9 “I was in the city of Joppa praying, and in a trance I saw a vision. I saw something like a large sheet being let down from heaven by its four corners, and it came down to where I was.  I looked into it and saw four-footed animals of the earth, wild beasts, reptiles, and birds of the air.  Then I heard a voice telling me, ‘Get up, Peter. Kill and eat.’  “I replied, ‘Surely not, Lord! Nothing impure or unclean has ever entered my mouth.’  “The voice spoke from heaven a second time, ‘Do not call anything impure that God has made clean.’
•• It was the very voice of God from heaven telling Peter to “kill and eat” from among the occupants of the sheet in the vision. Among those occupants that Peter was instructed by God to kill and eat were “four-footed animals”.
•• God, of course, was making the important spiritual point that Gentile humans were no longer to be considered “unclean.” To make that point, God instructed Peter to kill and eat animals that God was obviously now approving as food. Peter was commanded by God to eat meat.
Mark 7:18-19 “Are you so dull?” he asked. “Don’t you see that nothing that enters a man from the outside can make him ‘unclean’?  For it doesn’t go into his heart but into his stomach, and then out of his body. (In saying this, Jesus declared all foods “clean.”)”
•• This settles the matter, because “Jesus declared all foods ‘clean’.”Any religious “cleanness” issues pertaining to certain foods under the Mosaic Law were canceled by Jesus, who declared all foods to be “clean” for believers to eat. There is no obligation for the New Testament believer to follow dietary codes — for example, you may eat this, you may not eat that — that God, in His sovereignty, imposed upon Israel for a finite space of time (that is, the time of the Law).
Romans 14:1-2, 14 Accept him whose faith is weak, without passing judgment on disputable matters.  One man’s faith allows him to eat everything, but another man, whose faith is weak, eats only vegetables...  As one who is in the Lord Jesus, I am fully convinced that no food is unclean in itself. But if anyone regards something as unclean, then for him it is unclean.
•• The apostle Paul confirmed Jesus’ declaration that there is no remaining “uncleanness” in foods. In fact, Paul goes even farther by declaring that, from the religious perspective, it is the vegetarian or vegan whose “faith is weak”!
•• However, in closing, let’s be receptive to the apostle’s counsel concerning “accept[ing] him whose faith is weak” in this matter. It is not our place, nor my desire, to impose a meat or fish-based diet on anyone, including Christians who have scruples on this subject. Their decision in favor of going vegan or vegetarian is a personal one in their hearts before the Lord, and I respect that (Romans 14:5b-6).
•• My hope in this Bible study has been to give you some Scriptural validation for the biblically acceptable practice of eating meat and fish, as well as to establish that veganism and vegetarianism were not practiced by our Lord and Savior and are clearly not required of New Testament believers.
Summary: We have looked at five clear indications that vegetarian and vegan diets are not choices suggested by the New Testament.
1. Jesus ate meat with His disciples.
2. Jesus ate fish and gave fish to His followers to eat.
3. Peter was instructed by God to kill and eat animals.
4. Jesus declared all foods to be “clean.”
5. The apostle Paul said of the believer who chose a vegan or vegetarian diet for religious reasons that his faith was weak.