Many people have questions about the purity laws in the Old Testament: why are they there? What was the point? Was being unclean a sin? What about people with birth defects? Are women sinful for being so unclean all the time? Here are a few answers.
Israel was living on “holy ground” because God was physically with them. God’s physical presence demanded physical holiness by physical things around Him. Therefore you have purity laws.
Being unclean was not a sin; it was a fact of life in the presence of God. This is one main reason why we are told “flesh and blood cannot inherit the kingdom of God.” Being flesh and blood is weak and disgusting, and cannot exist in God’s physical presence.
It was, however, a sin to be unclean and go into the presence of God, or not do the purity sacrifices and so forth. That is disobeying God’s law. Being unclean was not a sin; being unclean and violating God’s law was.
The birth defects are the same issue. Levites with any birth defect could not serve in the temple where God physically met with His people. This doesn’t mean they are sinful, it means God demands as close to physical perfection as possible when you are physically with Him. I, as a legally blind guy, could not be a priest, which would’ve been fine with me!
The woman issue is again based on the physical stress of the old covenant. Women are more unclean simply because they have more unclean biological functions. I cleaned women’s bathroom’s for many years. I gotta tell ya, God has a point. Ask any janitor.
This does not mean women are sinful. It means they have less opportunity at being clean simply because of biology. Again, it doesn’t mean they are sinful, it means physically speaking they have issues of blood, as the KJV puts it, that make them physically unclean before God’s physical presence.
This is all merely my attempt to summarize what was going on back there and may not be correct, but I think when we remember the Old Covenant was largely physical for a physical people in a physical land meeting physically with God, it will clarify many issues.
It should also be noted that in the New Covenant we are told that in Christ there is no longer male nor female. Main reason being that the New Covenant is focused on spiritual things, not physical things.
Thus any biological distinction of clean or unclean is removed, which holds true for all other aspects of physical distinctions–race, birth defect, economic status, etc. that played a part in the Old Covenant separation of clean and unclean in God’s presence.