system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When soap breaks down the cellular membranes of cells why/how is it safe to use on our skin?
gpt
Our skin has a layer of dead cells on the top, as well as natural oils that form a somewhat protective barrier against certain things like soap.  When your hands dry out after washing them a lot, that is your oil barrier being removed.  Individual cells and viral particles pretty much don't have as thick of a lipid (lipids are fats/oils) layer as our entire skin surface does, so the soap degrades them more quickly.  Our bodies are also able to produce much more oil to keep our skin healthy than each little particle can, so after our hands dry out some we still have living cells beneath the dried out dead ones that can generate more oil.

  
However, not all pathogens are extremely susceptible to the killing effects of soap, which is why scrubbing and washing off vigorously for \~20 seconds is so important: good soap in the right concentration actually forms small little bubbles called micelles which surround dirt, pathogens and other debris, and allow them to become much more water soluble.  That slippery feeling is the soap working, so make sure you feel that before you finish scrubbing, and continue to scrub as you wash away with warm water!