"The key to freedom is obedience. The more obedient we are,                                   the more freedom we have." 
 I think this quote is trying to say that you need to choose the key to obedience to get freedom. If you don't use the key to obedience, you wont get freedom. That's why Boyd K. Packer want all the people to use the key and have freedom. The more obedience we are, the more freedom we have. Freedom is a good thing for people because you can be anything you want and choose the right thing to do. If you don't choose the right you won't have freedom and have a bad things you do.