We cause harm to ourselves by not having the courage and respect to look at ourselves honestly and gently. We cause harm to others by our actions, speech, and thoughts. Not causing harm is the basis of an enlightened society and the beginning of a sane world.
In ancient times people used to train in the mountains with a famous master, acquiring great wisdom, and abilities. No matter how much you train and how great your ability and wisdom, there is always somebody greater and wiser. Learn to recognize those and show them great respect.
Since the advent of civilization, we have exchanged our natural harmony for ego orientated lifestyles. Clinging to our old habitual ways of doing things keeps us chained to a lifestyle that violates our true nature. We have the ways and means to liberate ourselves, just look.
Look at your long-term priorities carefully and think about them. When you see opportunities, do not leap at them but wait for the right time to take action. If you want and desire without consideration of the consequences this could lead to all kinds of entanglements.
Quote: When knowledge and things interact, likes and dislikes arise.