Saying Leviticus is "outdated" is a pretty big slap in the face to Jewish people especially but also to Christians because while most Christians don't believe that we have to follow all the individual rules laid out in the Jewish Bible (such as eating kosher food, etc.) we do honor it and believe it to be the Word of God and also believe that some of it still does apply to us and guides us morally. For example, the fact that certain sins are considered worthy of death in the Jewish Bible doesn't necessarily mean we have to mete out the death penalty for them today, but it does indicate to us that God takes certain sins very seriously. Christians are not supposed to consider any part of the Bible to be "outdated" even if the way we put it into practice isn't going to be the same way that either ancient Jewish people or modern Jewish people would.