Beginning in Leviticus 21, the Lord turns from various instructions about living for His people to instructions specifically for the priests, and if you think He’s been a bit strict up to now, it gets worse for the priesthood.
The presence of a priesthood emphasized the holiness of God. Israel, though they were all God’s people and all called to be Holy, they were not able to come directly to the Lord. In fact, they were forbidden to do so. Anyone who tried was to be “cut off” from among God’s people, and therefore cut off from God (see Leviticus 17:1-9).
The function of the priesthood was to facilitate a relationship between God and the rest of Israel. They were also to help the people understand what it meant to be holy. They could not, however, do that job if their lives were but a mirror image of the community in which they lived. They had to be better, and they had to be different. The community was not allowed to eat the same food the priests ate.
It’s difficult for us to see grasp a relevance from all this for our lives, but perhaps these three points are at least implied:
As priests of God, Christians are not to mirror their community. The community does not lead us. We must live above the community, and the life must be so different that the community knows we are different – not just because we say it, or because of a haughty spirit, but because we act better. And in our own minds, we must remember that what God has promised to us, he has promised to no one else. We must believe that the rewards of holiness are superior to those prized and received by the community, for ours come from our preferential place with God.