Should Christians Be Vegans?

Being a vegan in church is probably like being a pacifist at an NRA meeting, or a Christian ACLU member. We’re just not that common. But why shouldn’t we be? There’s a lot that can be said about how the Church has conformed to a certain culturally conditioned means of understanding the world. It is anthropocentric and utilitarian in many ways. In other ways it is pessimistic and gnostic. These are all ways that it is unfaithful to the Gospel of Jesus Christ.
Jesus may or may not have eaten animals. I don’t know. In the gospel of John, he is depicted as cooking fish post-resurrection, but that’s the only story we have. Even then, some contend that the Greek says he ate some honeycomb, not fish. I’m not a Greek-reader so I can neither confirm nor deny this. Even if Jesus did eat meat, it would not have been often. Separated from food production as we are are, we rarely think about how what we eat is produced. Meat, for example, is very expensive to produce (about $35 a pound) and resource intensive (17 pounds of grain and 440 gallons of water for a single pound of cow flesh). It is the food of the rich. The 1st-century Jews would have eaten it on feast days, but that’s about it. The staples of their diet would have been bread, wine, olive oil, some dairy, and whatever garden vegetables and herbs they grew. From archeological discoveries we know they were prone to diseases like rickets and, overall, didn’t have very good nutrition. (This is why diet books flouting Jesus’ diet are absurd—though he probably was skinny, but from hunger!) 
Some do insist Jesus was a vegetarian (we have have an early gospel from the Ebionites insisting quite strongly on this point), others insist he was not, still others don’t care. Should we care? The scriptures say that “ a wise man has regard for the life/needs of his animal, but the tender mercies of the wicked are cruel” (Proverbs 10:12). Are we wise? Do we have regard for the lives of the animals with whom we share the planet? Or are we cruel in our wickedness? Modern animal husbandry is indeed cruel. Animals are confined so that they are unable to move; they are denied natural food and light, kept in constant states of pregnancy only to have their young taken from them. Cows, vegetarians by nature, are even fed the remains of other cows who have died. That's how mad cow disease started.
These are just a few practices. In reality, the entire process is cruel, inhumane, ungodly, and sinful. Jobs at a slaughterhouse have a 100% turnover rate,  and are very dangerous, with assembly lines that run so fast and so ineffectively that 25% of cows are dismembered while still conscious. This is wickedness.
Even if killing animals for food could be done in a way that did not cause suffering and was not resource intensive, I still would not participate. Why? Because my morality is shaped by my allegiance to God's goodness. For example, Genesis 1:29-31 reads,
“ 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.  God saw all that he had made, and it was very good. And there was evening, and there was morning—the sixth day.”
Though I do not read the creation story as a literal/historical event, I still understand this as representing God's intention for creation. God desired a world without bloodshed, not just between humans, but between all creatures. This is not the case, but we can still do our part to contribute to God's vision of peace. God desires harmony, not just "back then," but now and always. Harmony precludes unnecessary violence.

But what of sin? Since humanity is sinful such initial prescriptions are put aside in favor of a “grace” that allows permission for such things, doesn't it? Isaiah thought otherwise. Isaiah 11:6-9 reads:
The wolf will live with the lamb,
       the leopard will lie down with the goat,
       the calf and the lion and the yearling together;
       and a little child will lead them.
The cow will feed with the bear,
       their young will lie down together,
       and the lion will eat straw like the ox.
The infant will play near the hole of the cobra,
       and the young child put his hand into the viper's nest.
They will neither harm nor destroy
       on all my holy mountain,
       for the earth will be full of the knowledge of the LORD
       as the waters cover the sea.
Even in a state of rebellion, of sin, God still calls us to exercise peace at the level of inter-species relationships, and to take the lead, just as the child led them. Such harmony is even associated with having knowledge of God.If we truly have God's knowledge then we must cease to inflict needless harm on animals. If we refuse to do so, we do not know God. To paraphrase I John, how can we love God. whom we do not see, and not love our fellow creatures who we can see? If we cannot love them, then we cannot love God." Tough words. John applied them to humans, but there's no reason that they can't be applied to animals.

Jesus tells us that God cares for animals, and the OT is full of various laws to protect them. Perhaps those who think themselves wise or righteous should be more willing to consider the rights of animals, to consider that God loved the "world" (John 3:16), and not just humans. Perhaps they need to raise their consciousness a little bit, and begin to expand their sphere of compassion. Such a thing would be quite Christian. Jesus challenged his listeners to move beyond the Jew/Gentile binary, to include more than just Jews in their sphere of concern. It's time we moved beyond just humans as well.