What is the context?
The peaceable wisdom described at the end of chapter 3 stands in sharp contrast to the quarrels now addressed. James directs attention from the outward conflict to the competing desires within the people involved.
Craving, coveting, killing and fighting show the destructive course of desires that cannot be satisfied. James then brings prayer into the same picture. Some do not ask God; others ask with the purpose of spending what they receive on their pleasures.
This is a rebuke of self-seeking conflict and prayer, rather than a diagnosis of every disappointed request. The question is what the people want God to serve, as well as whether they are asking Him.
How is this passage commonly understood?
Calvin and Wesley both connect the quarrels with desires allowed to rule the heart and read the prayer warning as a rebuke of wrong motives. Wesley understands the language of killing as hatred in the heart; James supplies no account of a particular incident here.
Where does this fit in God's plan?
Galatians 5:13–15 contrasts using freedom for the flesh with serving one another in love. God’s purpose for the community is not satisfied by religious language added to rivalry.
1 John 5:14–15 describes confidence in prayer in relation to God’s will. Beside James, it directs asking toward trust in Him rather than an attempt to enlist His power for whatever the heart happens to crave.
What is our position?
Our study Prayer and Faith identifies two failures here: not asking God, and asking with motives directed toward self-gratification rather than His purposes. It also keeps the limit of the passage clear: James does not promise that sincere motives guarantee the outcome someone wants. His warning calls for examining the desire beneath the request.