What creates karma or effect?

The only difference between hell, and the majority view that the sins of the past are brought into balance, or are paid for in the present or in a future life, is the geography! 

God did not invent karma.

Karma is, in its essence, the law of attraction. 

Energy follows thought and actions follow thought. 

You would not act unless there were thoughts and beliefs that had led you to that action.

It is not the action that creates the karma―

It is the thought or belief behind the action that creates the karma or effect.

Each action has a motivating thought or belief, and beliefs are simply thoughts that have been thought over and over again until they become firmly rooted in the psyche. 

Therefore, the karma resulting from some action of yours is simply the operation of the law of attraction. 

It proves itself to you time and time again because this law responds to the beliefs that motivated the original action.

Johan L. Payne, Omni Reveal the Four Principles of Creation, 2001, Findhorn Press, United Kingdom, Chapter 3, How Can We Stop Judging?  35