Interestingly Jesus was not preoccupied with the law like the Pharisees were. Why is that? Critics say it's because the ancient Israelites did not understand the true nature of God. They thought that in order to make God happy strict laws and sacrifice was required. There are good reasons why ancient people felt this way. See Jehovah vs Jesus
Jesus revealed the true nature of God. The Pharisees were teachers of the law. Jesus taught us about God's love and matters of the heart. We know this because many years after Jesus died, followers were not sure if they needed to keep the law of Moses or not. And if so, which ones were required and which ones could be done away with. What did they do? Jesus wasn't there to guide them. So Christians along with Pharisees made up their own rules based on their own understanding. Acts 15:1-29
Even though Jesus could give us firm guidelines on whether blood transfusions are allowed or not, there is overwhelming evidence in the Bible that Jesus would break God's law in a heartbeat, if he could save a life.
Examine the facts in the following articles.