Purity
I encountered this quote the other day:
To the pure, everything is pure; to the base, everything is base.
At a closer look, this seems to be a paraphrasing of Titus 1:15:
Unto the pure all things are pure: but unto them that are defiled and unbelieving is nothing pure; but even their mind and conscience is defiled.
I have been doing a lot of thinking on this since. It seems to be true on many levels but also be somewhat paradoxical in a way that may be fruitful to meditate upon.
One place I think it can be seen: among people who seem completely inverted in their priorities and values. To them, the best parts of life, like having children or being part of a tight-knit community, seem like horrible evils to them.
Another level on which it is true is that everything done in light consists of only light. Done with a pure heart and clean conscience, very few things can truly be dark.
Many of the same actions can be good or bad depending on this. This is, on the small scale, the difference between a white and a black lie, or on a larger scale, white and black magic.
Obviously there are some things that definitionally cannot be done in the light (rape, murder) but if we ignore these types of definitionally evil acts, this becomes basically true of almost all actions.
This applies more to those who are somewhat spiritually conscious, but I think it remains true largely across the board.