I asked this because one can end up defining legalism, and Jesus is pushing things further.
The danger is always going from a healthy understanding of boundaries into continual self
condemnation. Take a simple idea. I think of someone who is beautiful. Appreciation of
various attributes arises. Now that could be called lust, or acknowledging my response to
them. Now dwelling on this emotion and using fantasy, now that is lust.
Some have a very imaginative mind, find themselves dreaming about individuals.
A cycle of condemnation and failure can then result, with suppression etc.
Rather than seeking help, they get eaten up, and leave the faith, or get so sensitive
about emotional reactions, refuse any contact with the opposite sex.
So a concept of purity is like poison, that triggers condemnation, guilt, and rejection.
So lock it all away, and hope it stays hidden. So addictions prosper, because honesty and
discussion is too dangerous, because the image is everything, and victory or balance is
no longer an issue of faith, it is just our little secret.
Legalism creates this environment, where truth of our fallen nature and lostness cannot
see the light of day.