Do you not know who that was written to and for what reason? It was written to Israel as directions to God's people for governing themselves in that specific time period for that specific people. ARE you trying to imply that because that appears in the Scripture that it applies to today? I know you both are more intelligent than that.
So EXACTLY what tools of reason do you use to determine what verses to abide by and which to ignore? You use plenty in the Old Testament as justification for your intolerance such as anti-homosecuality, the 10 Commandments, eye-for-eye and so forth.
Genesis was written for people who knew nothing about cosmology, geology, astrophysics and quantum physics. Yes you insist that it is the literal, inerrant word of God-a-mighty and outright refuse to even ponder anything that contradicts. So why don't us your your same "logic" to refute Deuteronomy as you do for Genesis?
There is only ONE tool which Christians use to receive and abide by God's specific directions and by which we glean spiritual meaning from scripture and that took, if you wish to call it that, is God's Holy Spirit that is given freely to each and every true Christian believer and Saint of God. Jesus promised that Holy Spirit in John 14 and God baptized each true believer at the moment of their true conversion and salvation through Christ Jesus. It's being born again (spiritually) not bodily. Spiritually and not physically, it's a profound substantial change of heart, mind, and direction of life such that people change overnight in a seconds time, the blink of an eye. Such a change that it is no less than miraculous and indis****bly (to the person/believer) of and by God. As for what to abide by or what is relevant to today and the past that comes through reading the book. Some is evident from the reading for it says who it's being written to. If it is not written to us then it isn't for us. If it is written to Israel then it's to Jews not to Gentiles. There are many things that are revealed, by God, through His Holy Spirit also.