Mark 9:42-49 contains several difficult statements from Jesus, most of them concerned with his metaphorical references to ‘salt’ and ‘fire.’ He says that “everyone will be salted with fire,” having just said that hell is a place where “the fire is not quenched” (v. 48). But in v. 50, he says that this fire which salts everyone “is good,” and he introduces the concern that salt may lose its “saltiness.” Finally, to complete v. 50, Jesus exhorts his followers to “have salt” in themselves and to “be at peace with one another.” The intent behind these juxtapositions is not obvious, to say the least, but this paper will argue that they make good sense if we postulate that the fire which salinizes in v. 49 is persecution and the force which prevents salt from losing its saltiness (v. 50). The structure of the argument leading to this conclusion will proceed in four steps. First, the paper will introduce the exegetical problems raised by Mark 9:42-49. Second, it will consider the most common alternatives in understanding this passage. Third, having found some difficulties with these other options, the paper will consider and defend the theory expressed above, viz., that the fire of v. 49 is persecution, with some references also made in this context to Matthew 5:13.