So what about those other Scriptures which indicate that works do have a part to play in man's salvation. In order to better understand how this relationship exists, let's look a James, chapter 2:
"But someone will say, 'You have faith, and I have works.' Show me your faith without your works, and I will show you my faith by my works. You believe that there is one God. You do well. Even the demons believe; and tremble! But do you want to know, O foolish man, that faith without works is dead? Was not Abraham our father justified by works when he offered Isaac his son on the altar? Do you see that faith was working together with his works, and by works faith was made perfect? And the Scripture was fulfilled which says, 'Abraham believed God, and it was accounted to him for righteousness.' And he was called the friend of God. You see then that a man is justified by works, and not by faith only." (James 2:18-24)
So, what relationship does works have to salvation and faith? How can we be justified by works? Let's examine the few verses which precede the above passage. "What does it profit, my brethren, if someone says he has faith but does not have works? Can faith save him? If a brother or sister is naked and destitute of daily food, and one of you says to him, 'Depart in peace, be warmed and filled,' but you do not give him the things which are needed for the body, what does it profit? Thus also faith by itself, if it does not have works, is dead." (James 2:14-17) Works -- good deeds which help our fellow Christians, spreading the gospel, etc. -- is what proves that our faith is alive and real. If we were to say, "I believe that Jesus is the Son of God," we would call that faith which can lead to salvation. But the proof of that faith, is not that we say we believe, but that we do those things which further the kingdom. Works are the result of saving faith. We are justified by our works, in that our works prove our faith to be real, alive saving faith; not just intellectual assent that God and His Son exist.
It is sort of like the old saying, "Put your money where your mouth is." It is one thing to say that we believe something, and another to conduct ourselves in such a manner as to demonstrate our belief.
Works and faith both together are essential to Christian life.
Peace