40-year activist Keith Akers recently appeared in the documentary Christspiracy to answer questions about why Jesus of Nazareth opposed animal sacrifice. I've read his 2000 nonfiction book The Lost Religion of Jesus: Simple Living and Nonviolence in Early Christianity, which goes into more detail. He wrote another book fifteen years later called Disciples that sounds like it has more research. This research into Jewish Christianity was sourced from writings from Jewish Christians, church fathers fighting “heresy.” and observant writers like Josephus living at the time. One was opposed to the sect, as was Paul who wrote many of the letters in the New Testament.
Jesus and his disciples, including many of his followers, were Jews and became known as Jewish Christians who believed that Jesus was predicted by Moses to reestablish Jewish Law, not to abolish it. They practiced simple living, nonviolence, and vegetarianism, making Jesus an ethical vegetarian.
Akers explains that there was so much heresy, such as from gnosticism, because Jesus was the first heretic for opposing animal sacrifice at the Jerusalem Temple. He preached mercy, not sacrifice. By doing so he incurred the wrath of the Jewish priests and was crucified by them. Akers points out that the gentiles stripped Jesus of his opposition, saying it was merely about opposing bad moneychangers, and left Jesus as a teacher without a cause with no reason to be murdered.
The first four centuries of the Jesus movement was very divisive and Christianity took over Judaism after several crises happened and the Roman Empire decided to put an end to heresies by claiming Christianity as the official religion.
Jewish Christianity died out not long after because they despised Paul for destroying Jesus' message and for Paul accepting some of Marcion's gnostic beliefs. They seem to have sprung up in Islam's Sufi beliefs, though. Sufi writers have extensively written about Jesus, stories not found in the Christian gospels.
Akers suggests that a great way to practice simple living, even nonviolence, is to become vegetarians. He explains that this will also greatly help our planet's health and feeding the poor. I agree!
Jesus of Nazareth didn't intend to create a new religion and he preached that the kingdom of his god is within us. Baptism restores our souls, not the idea that he died for our sins put out by gentiles. I greatly enjoyed this radical book that finally makes sense of Jesus' ministry and why the New Testament is often confusing.