"There is no discount in the law of justice and that we must pay 'the uttermost farthing.' The measure ye mete 'shall be measured to you again,' and it will be full 'and running over.'" (S&H)
There are three ways to respond to this imperative:
First, you can embrace Principle (knowing that "The design of Love is to reform the sinner."S&H) and maintain a state of doubting your own judgement, turning to God for guidance, and asking honestly, “Father reveal to me my secret faults,” striving to do what is right by Him.
Second, you can operate from the assumption that if you do not get caught by the human institutions (legal, religious, etc.), you are home free - moral idiocy. This state is punished here or hereafter "as long as the belief last."S&H
Third, you can recoil in fear that you will suffer for what you might have done wrong and carry a constant guilty conscience or anxiety. This state is self-perpetuated because all energy is used in clasping the wrong, instead of in releasing it and reforming.
Where is the mercy? As a mistake in math or in computer programming renders you helpless until the problem is corrected, so doing anything contrary to Principle, Love, must be corrected before spiritual harmony is reached. Since spiritual harmony is the true inheritance of man, mercy drives reformation!