What is Dead Faith? 

A dead faith is a faith that is not real. It is a said faith or an outward empty profession that is not deep. This would be someone who doesn't genuinely believe but pays lip service to belief. But what about believers with a living faith? You may respond by saying, "I should do more works to make sure my faith is't dead."  Yes we should do more works, but not to show God that our faith isn't dead. He already knows about your faith and has prepared works for you. We don't work to earn salvation. Abraham was declared righteous by God before he did any works. So works being a result of faith is the proper understanding.  For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; not as a result of works, so that no one may boast. For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand so that we would walk in them (Ephesians 2:8-10). 

James 2:14-24

What use is it, my brethren, if someone says he has faith but he has no works? Can hat faith save him? If a brother or sister is without clothing and in need of daily food, and one of you says to them, “Go in peace, be warmed and be filled,” and yet you do not give them what is necessary for their body, what use is that? Even so faith, if it has no works, is dead, being by itself. But someone may well say, “You have faith and I have works; show me your faith without the works, and I will show you my faith by my works.”  You believe that God is one. You do well; the demons also believe, and shudder. But are you willing to recognize, you foolish fellow, that faith without works is useless? Was not Abraham our father justified by works when he offered up Isaac his son on the altar? You see that faith was working with his works, and as a result of the works, faith was perfected; and the Scripture was fulfilled which says, “And Abraham believed God, and it was reckoned to him as righteousness,” and he was called the friend of God. You see that a man is justified by works and not by faith alone. 

James and Paul are not contradicting each other. They are preaching faith alone doctrine.

James 2:10 

For whoever keeps the whole law and yet stumbles in one point, he has become guilty of all.