I am not sure I will ever fully understand the rationale behind all of these laws. Certainly there were health reasons to seclude those who had communicable diseases, but that is hardly the primary reason behind these laws, since most forms of uncleanness had nothing to do with disease. I do think there are several important factors behind these laws:
- They reminded the people that God was King of every aspect of their lives, even the most intimate and personal matters.
- They reminded the people that God must be approached reverently, and if that was true with regard to physical cleanness, how much more was it true of spiritual purity?
- They made is impossible to mix sex with worship, which was sadly a staple of pagan religious practice (and a sin Israel was susceptible to in its history)
- They reminded the people that God is the God of Life, and therefore only those whole and complete could come before Him worship.