Leviticus 19 - This chapter presents many aspects of the Law that can and should be practiced today. Examples of this can be seen in verse 3 - giving respect to parents; verse 13 - pay your workers when you should; verse 31 - avoid fortune tellers and psychics. These practical injunctions can keep believers from offending a holy God and can help them live wholesome and productive lives.
Leviticus 20 - The death penalty was God's way of warning people to avoid sinful activity that requires such a judgment. I've often said that the death penalty in and of itself is not a deterrent to murder. But, carrying out the death penalty is!
Leviticus 21 - God expects those who serve Him as priests would maintain a high priority on their own personal holiness. They were not to act proud of their godliness, but they were to humbly honor God because they have been given the privilege of serving the Lord in this way. Today, as believers, we all serve the Lord as priests, and, therefore, we should have no less concern for our own holiness than the priests of Moses' day had on theirs.