Three times in this passage (James 2:14-26) the apostle says, “faith without works is dead” (vss.17, 20, 26). In verse 14, he indicates that a faith that does not have works cannot save. James is not saying that we are saved by works, but a genuine faith in Christ will be demonstrated by good works. In other words, people who have truly trusted in Jesus Christ as Lord and Savior will show or demonstrate that their faith is genuine or “alive” by their good works (see vs.18).
There is a faith which involves the assent of the mind without a change of the heart (see John 2:23-25; 1Cor.15:2). While James commends those who agree with the doctrinal position that there is one God, he warns them that the demons also believe this. Obviously, the faith of demons is not a saving faith, but they do tremble which may be more than the man James is confronting!
The faith that saves obviously includes mental assent, but it is also the faith that is exercised with the heart (see Rom.10:9-10). It is not a superficial faith that merely agrees with a doctrinal statement, but is experienced deeply in one’s being and results in a changed life exhibited by good works.
James includes two examples of people who believed God and later demonstrated the genuineness of their faith by their works. Abraham believed God in Genesis 15, and demonstrated his faith in chapter 22 when he intended to offer Isaac in obedience to the LORD. Rahab believed in the LORD and later demonstrated her faith by receiving and hiding the spies (Jos. 2:1-11; Heb.11:31). In essence she was serving the LORD by doing her part to see the LORD’s will accomplished in giving Israel the land of Promise. Both Abraham and Rahab are said to be justified by works, but James is using “justify” differently than Paul. By justify Paul means that God “declares righteous” the sinner who believes in Jesus. James is indicating that Abraham and Rahab were “shown to be righteous” by their works.