You Can't Earn It.

     There are those who feel as if they can somehow work their way into heaven. They believe that if they can begin to follow God's commands, they will become good enough to be accepted by God. They set about reforming their behavior. They give up bad habits, begin to be honest in their dealings with others, clean up their language, and many other things that they feel will gain the approval of God.
     This of course is impossible. Those who attempt to earn God's favor receive some bad news in His word.

     For as many as are of the works of the Law are under a curse; for it is written, "Cursed is everyone who does not abide by all things written in the book of the Law, to perform them."
     Now that no one is justified by the Law before God is evident; for, "The righteous man shall live by faith."
     However, the Law is not of faith; on the contrary, "He who practices them shall live by them."
                              Galatians 3:10-12 NASB

     This is telling us that if we would be perfect, acceptable to God, by the works of the Law, we must follow it perfectly. This means that we cannot slip in even one small point, if we would desire to earn God's favor.
     Perhaps an individual might decide to reform his or her life, and begin to flawlessly follow the commands of God. Even if they began to keep the Law, and never again disobeyed it, their past transgressions (breaking of the law), would condemn them. They are already lawbreakers, and no amount of good works performed by them, can atone for their sinful past.
     Of course it soon becomes evident to all those who have ever attempted to earn their salvation through good works, that the reforms and resolutions that they have attempted, have always ended in failure. A sinful heart cannot produce good works. A man may do some good things, even make some remarkable changes in his life, but in and of himself, he does not have the heart or will to live a life for God's glory. The world is filled with individuals who have tried to quit drinking, smoking, cursing, and lusting. They can all attest to the fact that they ultimately fail in their attempts to clean up their lives. The problem is in the sinful heart of man. A sinful man cannot and will not submit to God and His Law (Romans8:7-8).
     This is the problem; selfishness, man's desire to do things his way, in stubborn rejection of God. Yet somehow when feeling guilty, or fearing death, a man will try to make things right with God through works. Even his motives behind his reforms rise out of selfish ambition. Sinful man has no real desire to please God; he has no sense of sorrow over his sinful behavior. It is all about self preservation; avoiding the consequences of sin.
     Ultimately, we are all under the curse of the Law (Gal 3:10). The law we have broken (and we have all broken it), only condemns us. It cannot justify us. The Law of God shows us the heart of God, that we would love Him, and love one another. Mere law cannot induce one to obey it, it only shows us what to do, and when we have disobeyed it, it shows us that we are sinners.