Leviticus is a book of instruction, the do’s and don'ts for the Israelites. In these chapters , God wanted the Israelites to be different from the rest of the world. To conduct their lives in reverence and fear of Him .
Running through from chapter 18 ,19 and then 20 is the commandments of God and the punishments that follow those who break them .
He is never a respecter of persons . He stressed His disapproval of homosexuality, incest and adultery .
As believers we are called to stand out In the society .We must keep ourselves holy and not worship the gods(Molech as mentioned in chapter 20) of this world . Even though we are in the world we are not of the world.
Furthermore , God wants us to be our brother's keeper . In Chapter 19 God educates the Israelites on how to treat one another with fairness. To love the strangers as themselves ,to be righteous in judgement and not take unfair advantage of others.