I’ll give you my conclusion here at the front: the Bible has nothing against anyone being a vegetarian, but it doesn’t require it of us, either.
The place to start is at the beginning: Genesis 1.29-30: “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. And to all the beasts of the earth and all the birds of the air and all the creatures that move on the ground—everything that has the breath of life in it—I give every green plant for food.’ And it was so.” There is disagreement about this verse, with some saying that all were vegetarian at this point, with no life being taken to be used as food; others say that it doesn’t necessarily mean that, but it’s merely a generalization to show that all are fed from God’s hand—that what God creates, he preserves and provides for. Regardless, we can understand that early diets were diversified and complete, and that what was on the earth was sufficient to sustain life there. God is the source of provision for all their physical needs.
By the time we get to Genesis 9, sin has run rampant on the planet, and God has just finished with the time of judgment that is the Flood. God repeats the blessings and purposes of Genesis 1, but with some differences. In verse 3 humans are being given permission to be predatory hunters of food. Since the word used here (remes) specifically means “wild animals that travel in herds,” it is possible that they have already been using cows, sheep, and chickens for food. It’s difficult to tell. In any case, though, meat eating is authorized by God’s sanction as a way to sustain human life. God is not requiring people to eat meat; he’s just saying it’s OK to do so.
In Leviticus chapters 1-4 we find that the priests are allowed to eat some of the meat that was brought for sacrifice.
Isaiah 11.6-7 are usually called to the argument as asserting that in the future kingdom carnivores will no longer be predatory hunters. But these verses are pictorial, describing an idyllic, utopian paradise. It’s a vision of rest, not of the refreshments. It’s talking about peace, not food. The verses are about the elimination of threat and fear, so much so that even children will have no cause for anxiety.
Isaiah 62.25 teaches a similar truth. The point is not necessarily the literal veg-ification of wolves and lions, but that all devouring and poisonous aspects of our world will be gone. It will be a place of safety and peace.
1 Corinthians 10.25-26: “Eat anything sold in the meat market without raising questions of conscience, for, ‘The earth is the Lord’s, and everything in it.’ ”
So I return to the place where I started. Whatever you eat or drink, do all to the glory of God. Meat eating isn’t immoral or ungodly. One diet choice is not more godly than another. Jesus ate Passover foods and fish (Lk. 24.42-43), and fed the multitudes, as well as his disciples, with fish and bread.