Question:
Is justification accomplished by faith or by works, or both?

Answer:
The theological debate over the question of whether salvation is by faith or by works has caused Christian denominations to disagree for centuries. Differences of opinion are still common among Christians today. Some even say the Bible contradicts itself on the matter of faith and works.

This is just one of many Bible verses from the Apostle Paul
stating clearly that man is justified not by the law, or works, but solely by faith in Jesus Christ:
For by grace you have been saved through faith. And this is not your own doing; it is the gift of God…
Ephesians 2:8
Interestingly, the book of James seems to say something different:
You see that a person is justified by works and not by faith alone...For as the body apart from the spirit is dead, so also faith apart from works is dead. James 2:24, 26

Reconciling Faith and Works
The key to reconciling faith and works is understanding the full context of these verses in James. Let’s look at the beginning of the passage, which covers the relationship between faith and works:
What good is it, my brothers, if someone says he has faith but does not have works? Can that faith save him? If a brother or sister is poorly clothed and lacking in daily food, and one of you says to them, “Go in peace, be warmed and filled,” without giving them the things needed for the body, what good is that? So also faith by itself, if it does not have works, is dead.
But someone will say, “You have faith and I have works.” Show me your faith apart from your works, and I will show you my faith by my works. James 2:14-18,


Here James is comparing two different types of faith: genuine faith which leads to good works, and empty faith which is not faith at all. True faith is alive and backed up by works. False faith that has nothing to show for itself is dead.

In summary, both faith and works are important in salvation. However, believers are justified, or declared righteous before God, solely by faith. Jesus Christ is the only One who deserves credit for doing the work of salvation. Christians are saved by God’s grace through faith. Works, on the other hand, are the evidence of genuine salvation. They are the “proof in the pudding,” so to speak. Good works demonstrate the truth of one’s faith. In other words, works are the obvious, visible results of being justified by faith. Authentic “saving faith” reveals itself by works. From About.com Christianity