6 Wherefore, redemption cometh in and through the Holy Messiah; for he is full of grace and truth.
7 Behold, he offereth himself a sacrifice for sin, to answer the ends of the law, unto all those who have a broken heart and a contrite spirit; and unto none else can the ends of the law be answered.
Because the Holy Messiah is full of grace and truth, or power and light, He is able to reverse our trajectory and redeem (save) us from the negative consequence of our choices. Let me refer for a moment to Newton's laws of motion. The first law (paraphrased) says that "objects in motion will stay in motion until acted upon by some external force."
Imagine yourself on a frictionless skating pond. On one end of the pond lies happiness, and at the other end misery. One day, you make a choice that propels you in the direction of misery. Because the skating pond is frictionless, you will be unable to turn, to steer, or to alter your course in any way. You have become subject to the law. The laws of motion have not been broken, nor can they be. Otherwise they would be called the "guidelines of motion." You made a choice, and the law simply enforces the consequences of your choice, they same as they would if anyone made the same choice.
Now imagine you have a friend standing on the ice who sees you careening towards misery. In an effort to save you, your friend reaches out her hand and grabs you. To her surprise, she will find that both of you are now sliding towards misery together. Without friction, the amount of force that she can apply is very limited. In fact, any amount of force that she applies to propel you in the direction of happiness will necessarily force her in the direction of misery. This is Newton's third law. For every force, there must be an equal force in the opposite direction.
You may have heard that Chuck Norris doesn't do push-ups, he pushes the earth down. Actually, this is half true. With every bit of force that he pushes down on the earth, the earth pushes back in the opposite direction. Perhaps a better example is two friends on the frictionless skating pond. If both friends stand still, and then Friend 1 pushes Friend 2, what will happen? If you said that Friend 2 will go sliding away, you are only half correct. Let's assume for now that these friends are the same weight. Even if Friend 1 does all the pushing and Friend 2 does not push back, Friend 1 will be propelled backwards at the same speed that she propelled Friend 2 forward.
So what does all of this have to do with 2 Nephi 2? Redemption comes through the Holy Messiah because "he is full of grace and truth," or might I say, full of forward momentum. Christ is so full of grace and truth that he has the power to right our wrongs. He can apply enough saving force to stop our slide towards misery and propel us towards happiness. Of course, being slow to learn we will inevitably make more choices that will cause us to start backsliding, but as many times as we let Him, He has the power to turn us around again.
So how do we take advantage of His 'forward momentum?' By a broken heart and a contrite spirit. All it takes is for us to recognize that we have made the wrong choice, and to feel regret for our actions. Once we realize that we have made a mistake, and that no amount of skating, kicking, or flailing is going to fix it, we can ask Him to help us make it right. If we do this, then the law has been satisfied.
The dictionary has many definitions for the word "end," but there is one which I think best fit its usage here. I don't think that it means "the termination of a state or situation," or "death or ruin," because the law is eternal and has no beginning or end. It could mean "a goal or result that one seeks to achieve." However if the law has a goal that it is meant to achieve, it must have been created at some time by someone in order to meet that goal. That also does not seem possible if the law without beginning or end. The definition that I think fits best is "the furthest or most extreme points of something."
The laws of motion can not be broken, nor can the eternal laws be broken. If Christ had not sacrificed for our sins, the eternal laws would not be broken. We would be careening towards misery with no hope of redemption because of the law. Thankfully, with Christ as our Mediator and Savior, he can answer the ends of the law on our behalf.