This is a rather ongoing debate amongst different institutions that call themselves Christian--and, yes, I am implying that not all of them are. If you look at the works that spring from some of their beliefs, I'm sure you would agree.
Some say that we can't get to Heaven without our own good works. They say that God would be allowing untold wickedness to enter His Kingdom unpunished, if that were the case.
My question to them is, "Was it really unpunished?" Did not Jesus suffer the punishment for all of our sins--past, present, and future? God Himself has paid for the wickedness of those He calls His own; that is the Good News that we preach to mankind!! If you have to preserve yourself, how can you be sure you will get to Heaven?
"Ah," some say, "but you can't be sure: to be sure that you will get to Heaven means that you most definitely will not." Nothing could be further from the truth. The Apostle John said, "These thing have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life..."(I John 5:13) St. John is promising us that if we believe on Jesus as our Savior, we can be sure that we will get to Heaven. Jesus said the same thing: "For God so loved the world, that He gave His only begotten Son, that whosoever believeth in Him should not perish but have everlasting life" (John 3:16).
Now what is so significant about believing that Jesus will save you? "Whosoever shall call upon the name of the Lord shall be saved. How then shall they call on Him in whom they have not believed? And how shall they believe in Him of whom they have not heard? and how shall they hear without a preacher?" So then, one must believe on Christ in order to ask Him for salvation from sin and it's awful consequences. [Because many believe that He will save them, but they don't ask because they don't want to escape. They are under the delusion that it would not be right for them to escape while others perish (the others chose to perish; it's not like God didn't offer them salvation, too) or that it will be "no fun" to be in Heaven amongst all those "goody-two-shoes," having to follow God's rules. I don't understand how burning in Hell can be more fun than praising the Lord, and I don't see how sin can ultimately bring more pleasure than righteousness. I have sinned many a time. I like doing right a whole lot better!!!]
But then, is it not a work to call upon the Name of the Lord? I don't see how: you are asking somebody else to clean up your mess; that's working?
Some will say, as the others have predicted, "Well, let's live it up! Let us sin that grace may abound!!" Have these people truly repented? Do they understand that Jesus came to "destroy the works of the Devil" (I John 3:8b) and that those who still want to perpetrate the works of the devil are still the enemies of God and children of the devil (I John 3:8a and John 8:44)? You get saved because your own sin has hurt you and you don't want to continue unto the fullness of your reward. If you enjoy sin, why get saved?
So then if you are truly saved, there are sins in your life that you will abandon as time goes on. These are the fruits of the Spirit, which show that you have the spirit of Christ indwelling you and therefore that you are indeed Christ's and no longer under condemnation (Rom. 8:1-13).
If you don't give up those sins, prepare to live a very miserable life. I have heard several testimonies that the most miserable person in the world--is the Christian who won't repent. The Holy Spirit backs up the conscience of a person who has received Christ. If that person continues in iniquity, he will soon find it hard to even be awake. He will sustain rebukes at every turn, he will have his prayers thrown back to him, he will not be allowed to rest, until he repents.
People who have not grown up in church all their lives seem to realize this, and that's why Christianity is such a sharp break for them. They know that they will not be allowed to sin "freely", and unless they really want to escape their sins, they will not come to Christ at all (cf. John 3:18-20).