"We can most easily understand karma by how we understand other laws of cause and effect.  Each moment sets up the conditions of the next moment.  Such understanding supports all our science in the laws that govern matter, life and mind.  The law of karma works the same way.  Each moment of intentional action conditions or sets up the next moment in a chain of causes and effects governing choices.  Each moment of choice creates effects that produce the kind of mind and world we have in the next moment.  Every volitional choice always affects the mind.  Every choice bends our inclination ever so slightly in one direction or the other—thus choices form character.  Whenever we surrender to a discordant impulse, it becomes easier to surrender the next time.  Each helpful ‘no’ to unwholesome whims makes it easier to say ‘no’ again.  Choices always have this consequence.  How we handle choices conditions the next moment in the mind.  Inch by inch, we ‘grow’ ourselves in some direction."

--Mary Jo Meadow, Kevin Culligan and Daniel Chowning, Christian Insight Meditation: Following in the Footsteps of John of the Cross