Both Revised Standard Version and Good News Translation have combined these two verses in one sentence. In Greek what James says here is literally “(7) For let not that man suppose that he will receive anything from the Lord, (8) a double-minded(-souled) man, unstable in all his ways.” There are some problems in punctuation and the arrangement of the clauses. Several ways of understanding the verses are possible.
(1) We may place a major break after verse 7. “A double-minded man” becomes the subject of the second sentence. This makes verse 8 a general statement. This means that “that person” who “supposes” in verse 7 may not be the same person who is “double-minded” in verse 8. Thus King James Version has “For let not that man think that he shall receive anything of the Lord. A double-minded man is unstable in all his ways” (similarly Barclay, Phillips, and New English Bible margin). In this case that person refers to the “doubter” in verse 6b.
(2) A second possibility is to take the “double-minded” person in verse 8 as the subject of “receive” in verse 7, as Revised Standard Version has done: For that person must not suppose that a double-minded man, unstable in all his ways, will receive anything from the Lord. In this case that person is identified with the one who asks in verse 6a, not the “doubter”; he is being reminded that the doubter’s prayer will not be answered. This understanding, while possible, is unlikely, in that this is not the most natural rendering of the Greek order. Further it suggests that the person “supposing” and the “double-minded” person are different people.
(3) A third possibility is to take the double-minded person as in apposition to that person of verse 7, making verse 8 an added description of that person in verse 7. This can be done in three different ways.
(a) Make verse 8 a participial phrase describing that person. Thus “For let not that man expect that he will receive anything from the Lord, being a double-minded man, unstable in all his ways” (New American Standard Bible [New American Standard Bible]; similar also Goodspeed).
(b) Put a major break at the end of verse 7, but identify the double-minded person in verse 8 as that person in verse 7 by providing “He is….” In this case “He” will be the subject of the second sentence, and “the double-minded man” will be the predicate descriptive of “he.” Thus “A man like that should not think he will receive anything from the Lord. He is always in two minds and is unstable in all he does” (Revised English Bible; similarly La Sainte Bible: Nouvelle version Segond révisée, Translator’s New Testament, Die Bibel im heutigen Deutsch, New International Version).
(c) Combine the two verses in one sentence. Since the double-minded person is an appositional description of that person, it is best to bring that description closer to that person. Thus “If you are like that, unable to make up your mind and undecided in all you do, you must not think that you will receive anything from the Lord” (Good News Translation; similarly New Jerusalem Bible, New Revised Standard Version).

In all these cases that person in verse 7 still refers to the “doubter” in verse 6b. To use inclusive language we may follow the New Revised Standard Version rendering by identifying the subject of verse 8 as “the doubter” or making the subject “you” as Good News Translation has done.

On the whole, the third possibility seems to fit the context better, and it is at the same time more intelligible. In order to make translation easier into languages that customarily do not use appositional statements, the verses can be broken down into two complete sentences: “That kind of person is unable to make up his mind and is undecided in all he does. He must not expect that he will receive anything from the Lord.” Contemporary English Version follows more or less this pattern and therefore may serve as a model for restructuring: “If you are that kind of person, you can’t make up your mind and you surely can’t be trusted. So don’t expect the Lord to give you anything at all.” The translator may also reverse the order of the sentence in some languages and say “Such a person must not expect that the Lord will give him anything. He is a person who is unable to make up his mind, and is undecided in all he does.”

The expression that person has a tone of disapproval or contempt, and so is rendered accordingly by a number of translations; for example, “That sort of a person” (New Jerusalem Bible), “A man of that kind” (New English Bible), “A man like that” (Revised English Bible). That sort of a person is a double-minded man (so also American Standard Version [American Standard Version]). The word “man” in Greek is normally the word for a male person but is here used in the general sense of “person.” The word double-minded, literally “double-souled,” occurs in the New Testament only in this letter, here and in 4.8. The soul is believed to be the seat of emotions, desires, and will. A “double-souled” person is one who lacks “single-mindedness,” who is torn between conflicting desires and wills. He is a person of “divided loyalty” (Phillips), someone who “can never make up his mind” (Barclay), is “indecisive” (Bible en français courant), and “irresolute” (Goodspeed; so also La Sainte Bible: Nouvelle version Segond révisée). This indecisiveness can be rendered literally and idiomatically in some languages as “be of three hearts and two minds,” or simply “be of two hearts.”

The double-minded person is further described as unstable in all his ways. “The person who in prayer lacks certainty with regard to God is also in his conduct lacking in inner stability…” (Dibelius). The adjective rendered unstable is used in the New Testament only here and in 3.8 (“restless”). The imagery is that of a person incapable of walking steadily, “unable to steer a straight course” (Barclay; similarly New English Bible), and “wavering” (Moffatt). This kind of person is uncertain in all his ways. The word ways, a common Old Testament expression, is often used for a person’s daily life, its conduct and affairs. This is rendered in various ways; for example, “about everything he does” (Goodspeed), “in all you do” (Good News Translation), “in all he does” (New International Version, Revised English Bible), “in all his conduct” (Translator’s New Testament), and “in every activity” (New Jerusalem Bible).

It will be noted that here, as in 3.9; 4.10, 15; 5.4, 10, 11, the word Lord refers to God, not to Christ. God is the giver of gifts (1.5, 17). In a number of languages it may be necessary to identify Lord as God, because Lord is used of Christ in verse 1.

Quoted with permission from Loh, I-Jin and Hatton, Howard A. A Handbook on The Letter from James. (UBS Handbook Series). New York: UBS, 1997. For this and other handbooks for translators see here .