Identifying the subject referents in the various clauses in James 2:18-19 has its challenges. Dibelius (James. Hermeneia.1976, 154) describes this text as “one of the most difficult New Testament passages in general.”

1. Who is tis (Greek indefinite pronoun = “someone”) in 2:18? It probably is not a masked reference to the author himself. There is no need for him to adopt such a literary fiction. Further, this interlocuter does not oppose the tis in v. 14. In other words James is not introducing an “ally” in v. 18. Rather, this use of “someone will say” reflects a common feature of dialogue within diatribe to introduce another objection to the argument being engaged.
2. Where does the opponent’s response end? Dibelius argues (154-56) that only the words “you have faith and I have works” form the opponents response. Thus vv. 18b-19 form James answer to this objection.
3. The challenge to this proposal regarding the opponent’s statement (“you have faith and I have works”) is that on the surface it seems to be the reverse of what we might expect. The opponent seems to say what we would expect James to argue, based on vv. 14-17. Dibelius reponds to this objection by suggesting that the “you…I” language in v. 18a, expresses two categorical positions. Some people claim faith and some people claim works, and regard them as separate and distinct. So the referents of “you…I” are indefinite people making such claims from time to time.
4. James responds to this position that keeps faith and works separate with two arguments. First, he challenges the opponent to “show me your faith apart from works” (v.18b).  Of course, this is not possible. Rather, as James asserts, faith becomes apparent or plain by the works motivated and empowered by it.
5. In the second argument he uses the cognate verb pisteuō (“to believe cognitively”) to describe the knowledge that demons share with humans about the reality that “God is one” (v. 19). For James, this is an example of “faith that exhibits no works” and that produces no benefit to the human confessor. However, this kind of “faith/believing” that demons possess and express does not equate with “personal confidence and trust in the Messiah that saves.”

Without doubt this text in James will continue to exercise exegetes’ abilities. The solution proposed and based upon Dibelius’ arguments is one option, but one that seeks to make sense of the text as we have received it. Punctuation, of course, is a more modern innovation and so we cannot rely upon Greek manuscripts to help us resolve the punctuation issues.