A. "The end justifies the means" is a phrase which means that if you have a goal it does not matter how you reach it, as long as you reach it. For example, say that your goal is to get an A on a test. If you believe that the end justifies the means, cheating on the test to get the A does not matter to you. All that matters is that you got the A. And you cheat!
B. "The end DOES NOT justify is a phrase that means" means that you must take a proper/moral route to reach your goal. You cannot break the rules or do anything bad or dishonest to reach your goal. If you wish to get an A on a test and you believe that the end DOES NOT justify the means, you would probably study harder or more and use other legitimate means to get the A on the test. You cannot do bad to get to a good outcome.
C. As only God knows the end from the beginning we can never know that our goal will be met by use of any means, including unjust means. Therefore, the means must always reign supreme over the end. Hence, The Way.