In these two verses the writer issues a warning to his readers. He seems to be speaking consciously as a prophet. Good News Translation places the two verses within quotation marks in order to make clear that the two verses are directed at the readers of the book; also similar is Bible en français courant.
If any one has an ear, let him hear: this is like the exhortation at the end of each of the letters to the seven churches in chapters 2-3 (see 2.7, 11, and the others).
The translator may consider translating the next sentence as poetry, as Revised Standard Version does (see Section F in the introduction, “Translating the Revelation to John,” pages 6 and following).
If any one is to be taken captive, to captivity he goes: for this and the next statement, see Jer 15.2; 43.11. The meaning here is that any believer who is destined by God to be imprisoned will surely be imprisoned. It is likely that this is more than an affirmation that such a person’s arrest and imprisonment is inevitable; it is a way of counseling that person to submit to arrest and imprisonment, without trying to escape his or her God-given destiny. In languages that do not use the passive, one may say, for example, “Whoever must be a captive will be one” or “Whomever God has destined for them (unknown agents) to take captive will be a captive.”
If any one slays with the sword, with the sword must he be slain: this translates a Greek text that is different from the text translated by Good News Translation. The text translated by Good News Bible (UBS Greek New Testament) is based on one very important early Greek manuscript; the other text is supported by most Greek manuscripts and early versions. It is interesting that most modern translations are like Good News Bible; of those consulted, only Moffatt, Phillips, An American Translation, and New Revised Standard Version agree with Revised Standard Version. But most commentaries consulted (Swete, Beckwith, Caird, Sweet, Beasley-Murray) agree with the Revised Standard Version text; only Charles differs.
The internal evidence favors the text translated by Good News Translation, because it is a parallel to the first part of the verse (and see Jer 15.2; 43.11). The Revised Standard Version text expresses a thought like the one found in Matt 26.52, a warning to Christians not to use a sword in their own defense. It is impossible to be dogmatic about which text is to be preferred; everything considered, it is recommended that the text translated by Good News Bible be followed.
Killed by the sword is referring to people being executed for their beliefs. So it is possible to translate “Those persons whom God destines to be executed will be executed” or “… for people to kill (or, execute) will suffer execution.”
Here is a call for the endurance and faith of the saints: see 14.12 for a similar statement. The Greek text says simply “Here is the endurance and the faith of the saints.” This is not so much a statement of fact as an exhortation, “This means that the saints must endure and be faithful.” Awareness of the fact that it is God’s will that many of them be imprisoned and slain calls for endurance and faith on their part. For endurance see 1.9, and for faith see 2.19. It is probable that here the Greek word means “faithfulness,” as New International Version, Nova Tradução na Linguagem de Hoje, and Revised English Bible translate it; New American Bible, Revised translates the whole phrase “faithful endurance.” For saints see 5.8. So one may translate “This means that God’s people must endure faithfully.”
Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on The Revelation to John. (UBS Handbook Series). New York: UBS, 1993. For this and other handbooks for translators see here .