There’s a trap that all of us fall into from time to time. It’s called the “ancient people were stupid” trap. The basic premise is that we are far more enlightened now than they were then. Therefore, our opinions about various issues must be right. While it is true that the past contains perplexing (the earth is flat) and grotesque (slavery is normal and acceptable) viewpoints, this type of thinking is dangerous. Especially when Christians start to think that the Bible was written by and for people who had no idea about the issues we would face today.
That kind of thinking puts us on a slippery slope. If we pick and choose the parts of the Bible we think still apply based solely on what we like and don’t like, it shows that we don’t believe in biblical authority. We have made ourselves the final authority. We have set ourselves ahead of God. We are guilty of making God into an idol that serves our interests and needs. And if we do that, why would we bother to believe in God at all? Why not become our own god and live however we want?