"When obedience becomes our goal, it is no longer an irritation; instead of a stumbling block, it becomes a building block."
     -James E. Faust 

This quote is trying to say that obedience can be something hard, irritating but if you take obedience as a goal, it won't be an irritation anymore. If you get use to obey, it won't bother you to obey anymore. 

"Obedience is central to becoming, being, and remaining Happy."
    -David Bednar

This quote is trying to say that if you are obedient, you will be happy. If you obey the rules, choose the right, do well, you will receive freedom, and freedom is Happiness.
For Example: If you obey the home rules, your parents will let you the freedom to go to parties, and in the parties you are happy.

   

"The key to freedom is obedience. The more obedient we are, the more freedom we have."
       -Boyd K. Packer

This quote is trying to say that if you are obedient, you will be awarded with Freedom. If you are more obedient, then you will have more Freedom. If you don't obey, you will be punished and you will have no Freedom. 

"Obedience is the Great Test Of Life"
      -Thomas S. Monson

      This quote is trying to say that Obedience is Something Very Important in Life. If you obey, You will be successful in life. Sometimes being Obedient can be a little hard, But if you are an Obedient Person, you will be awarded. If you are a Disobedient person, Don't follow rules and don't do what you are supposed to do, you will be Punished.