It’s okay to say “I don’t know,” especially when talking about the Bible or answering someone’s objections.
I don’t know for sure who the people before the flood (antediluvians) married. I assume brothers married sisters for at least a while, but I don’t know. Later, it appears this was not something to continue because God tells us to stop.
I don’t know who the “sons of God” were that took daughters from the “sons of men” in Genesis 6:1-4. I know that it wasn’t good. It seems to be connected to the wickedness of man being great on the earth (Genesis 6:5). But I don’t know for sure.
I don’t know for sure, but I’ve got a good idea that people in the Land before Israel moved in needed to be wiped out. They were asking for it. Every abomination conceivable at the time was in practice in Canaan. Children were routinely sacrificed. Sexual perversion was out of control. Leaders were defiant towards God and God’s ways. Their own actions caused the wiping. There were no innocents. The only option was to be removed from breathing for a while.
“Do not make yourselves unclean by any of these things, for by all these the nations I am driving out before you have become unclean, and the land became unclean, so that I punished its iniquity, and the land vomited out its inhabitants. But you shall keep my statutes and my rules and do none of these abominations, either the native or the stranger who sojourns among you (for the people of the land, who were before you, did all of these abominations, so that the land became unclean), lest the land vomit you out when you make it unclean, as it vomited out the nation that was before you. For everyone who does any of these abominations, the persons who do them shall be cut off from among their people. So keep my charge never to practice any of these abominable customs that were practiced before you, and never to make yourselves unclean by them: I am the LORD your God.” (Leviticus 18:24–30, ESV)
I know. It sounds like today, doesn’t it? I certainly want to spew when I see actions from people like Miley Cyrus or other so-called entertainers. I don’t know why people are repeating the same abominations that caused the destruction of the antediluvians or the Canaanites, or that will cause the destruction of what we see very soon. But I know it’s going to happen. We’re asking for it.
Maybe my understanding needs a little help. Maybe the text is not translated correctly. Maybe I just need to keep reading and keep pondering. Or maybe there are more things from His Word I need to be doing in my life, and as I add those my understanding will increase and I’ll figure it out. I don’t know.
That’s okay though. It doesn’t affect anything, because I know that God is good and merciful and whatever He had to do was needed and the only option. Whatever He does with the current Canaanites and pagans will be in the same vein. He created; He can do what He wants with His creation. In the meantime my understanding is good enough to know what He requires of me. Do what He says. All the other stuff will become clear. What he wants from me is very clear. I may not know about some of the things in the Word, but I know this: He is love and will always act in accordance with love. Even His judgment is from love.
If I don’t know something, it doesn’t detract from who He is, or what He wants. When we get in the middle of talking with people it’s no shame to say, “I don’t know.” I don’t know about a specific thing that happened 6,000 years ago, but I know what He wants from me. And I know what He wants from you. Do what He says. Avoid abominations. Abide in His Word. Repent. Turn from our own ways to His.
That part I know is very clear.