Then the Lord spoke to Moses, saying, “Speak to the children of Israel, and say to them: ‘I am the Lord your God. According to the doings of the land of Egypt, where you dwelt, you shall not do; and according to the doings of the land of Canaan, where I am bringing you, you shall not do; nor shall you walk in their ordinances.'” (Leviticus 18:1-2)
In the last chapter, God addressed consumption of blood and sacrificing to idols, both of which were commonly practiced in Egypt. In this chapter and the next, God addressed immorality and forbidden relationships, both of which were rampant in Canaan. In other words, God took them from one place that was infamous for certain types of sins and into another land infamous for other egregious and destructive behavior.
In a sense, these two nations represented two of the most morally decadent in the world at that time. So He purposely took Israel out of the worst situation in one way and led them into the worst in another way. Why would He do such a thing? It occurs to me that it was, at least in part, to accentuate the need for His people to be alert to the environment they were in and, in spite of what the locals do, remain holy. Just because everyone else does it is not justification for God’s people to do it — whatever “it” is. In short, Israel was to be “set apart” even when they were up close and personal with the nations of the world.
Culture, ancient or modern, is an accumulation of practices, many of which are not necessarily based on logic but on what is deemed acceptable. Consequently, one society might regard another as primitive and barbaric, and at the same time, turn a blind eye to their own barbaric practices (like abortion maybe?). Israel’s (God’s people’s) “culture” is not based on practices ordained and adopted by man but prescribed by the Creator. Holiness is that standard and is defined for us in the Word of God.
Therefore, as His people, we mustn’t let modern society teach us what is right and acceptable — especially when it encroaches on what the Creator has said. To the contrary, regardless of the cost, it is our duty to heed God’s challenge to “Come out from among them and be separate” (2 Corinthians 6:17).
Blessings and Shalom,