The law functions in the life of the believer in several ways in James. James calls it the royal law – it is the law of the kingdom. I think it's broader than just Leviticus 19:18, but in any case, this is the perspective that James has on the law; it's the law of Jesus' kingdom. And certainly that means that the law, as James sees it, is not a set of rules. It's not a series of do's and don'ts. Rather, James sees the law as a revelation of God's character, and therefore James is not really interested in the kinds of questions that many Jewish interpreters of the law were interested in. He never mentions circumcision, he never talks about the Sabbath, he doesn't talk about the ceremonial law, he's not interested in food laws. Rather, James is interested in the big issues: showing mercy, caring for the poor and respecting them, showing genuine humility, endurance in the face of suffering, and perseverance in prayer and such things. Furthermore, James indicates that he's concerned with the way the law as a whole functions, and that means that you don't get to pick and choose which laws you command. He says if you don't commit adultery, that's fine, but then if you go and commit murder, then you're still a lawbreaker. James seems to conclude that with a focus on the thing which most counts, which is showing mercy. He even says mercy triumphs over condemnation, because it's God's character of mercy that really is the controlling feature, the controlling idea of the law as God gave it. James also refers to the law as a perfect law in chapter 1 verse 25, which he says is a law of freedom. So, this is by no means an enslaving use of the law such as Paul condemns in Galatians. James sees this law as a revelation of God's character as something which is liberating. And the reason it's liberating is because, somewhat like a mirror, James says, it's where you can see the character of God, where you can see genuinely God's image. If you look into an actual mirror, what you see is a reflection of somebody who is made in God's image – yourself – but is a very poor reflection in many ways. But when you look into the perfect law, what you see is a reflection of the image of God as he actually is. And as we gaze at that image in faith, we are transformed into that image, and thus we gain the character of God and then the blessing of God.