James continues to accuse these dispersed believers "murderers." Very likely, they are not literally committing murder, but are slandering and cursing one another. They are failing miserably at controlling their tongues, as James indicates in chapter 3. But rather than call them slanderers, he repeatedly calls them murderers. Why? Because he is attempting to pry open their hardened hearts so that they will hopefully be convicted by the Holy Spirit of their villainy toward one another - villainy that they seem to care very little about, but something that deeply grieves God.

James 5:6