Christianity is separated from other major religions by this biblical truth: There is nothing man can do to earn the favor of God. Salvation in other religions is dependent on the good works of man to please the deity, or to ensure one's favored place in the cosmic scheme of things. Only Christianity sets man's good works aside and focuses salvation on the grace of God.
Even with that biblical clarity, Christians still get confused about the place of good works. It is best understood this way: Christians are not saved by good works, but they are saved for good works. Ephesians 2:8-10 could not be more clear: We are saved by grace alone through faith in order to accomplish the good works for which God saved us. Our ongoing works, carried out for God, become a sign and testimony of the reality of our salvation. A person saved by grace stops working for self and begins working for God.
Christ's work on the cross removed any necessity of our works for salvation. Our works are an expression of gratitude for His.
Anyone can devise a plan by which good people go to heaven. Only God can devise a plan whereby sinners, which are His enemies, can go to heaven. Lewis Sperry Chafer