So who is wrong? Moses or Jeremiah? Both prophets! One is lying. Are they all lying? Is Jesus lying? We have a saying in India when you cook rice, you check only one grain. I find the grain false. What is to prove that they are all not lying? Just making up what is convenient to them at that time.
Note: I am not against Christianity as a personal belief. What rankles me is preaching (which perhaps should not be done in this forum).
You are the one using the word "preaching". Why not "interfaith" discussions? I hope you are not against interfaith discussions.
Moses was not wrong. He simply used "pichuach nephesh" to succeed effecting the Exodus from Egypt. Pichuach nephesh is an allowance in Judaism to break a commandment in order to uphold a more important one.
Moses had been commanded to take the Israelites out of Egypt and, probably, he had been questioned about sacrifices as part of the religion of Israel and, probably he must have denied them as a pagan method to worship.
Realizing that he had made a mistake and would lose the chance to fulfill God's command, he used pichuach nephesh by saying that God had ordered the sacrifices.
Since with History the Israelites were exaggerating with those rituals, Jeremiah revealed the secret that God had never ordered sacrifices of animals. (Jer. 7:22)
Therefore, neither Moses nor Jeremiah was lying. Evidence of the fact is that, if sacrifices had been ordained for the sins of the people, how could be explained that after 70 years of exile in Babylon with not a single animal sacrifice, at the end of the exile, the sins that had caused the exile had been forgiven to all? (Dan. 9:24)