I have told you this appears first in 14.25. The reference may be to the previous verse, but it more likely refers to the entire discourse, at least as far back as 16.1.

So that you will have peace by being united to me is more literally “so that in me you may have peace.” For the meaning of peace, see comments on 14.27. Barclay translates “that in me you may have all that makes for true happiness.” The meaning of “in me” is either “in union with me” or “in fellowship with me.”

The phrase by being united to me expresses means. It may be rendered in some languages as causative, for example, “so that your being united to me will cause you to be truly happy.” In some languages means may be expressed by a clause introduced by “because,” for example, “so that you will have true happiness because you are united to me” or “… because you are one with me” or “… joined to me.”

The world will make you suffer is literally “in the world you have suffering.” Structurally “in the world” is in contrast with “in me.” Since the world refers to the world of evil in its opposition to God (see 1.10), Good News Translation restructures to indicate that the world is the source of the suffering brought on the disciples. The word used here for “suffering” (thlipsis) is the same one used in verse 21. Elsewhere in the New Testament it is used to refer to the sufferings believers must endure (see Mark 4.17; 13.19,24; Acts 11.19; Eph 3.13; and Rev 7.14).

But be brave is a word of encouragement (New American Bible “But take courage!”; New English Bible “But courage!”). An admonition to be brave may be expressed in some languages in an idiomatic form, for example, “stand up to the danger” or “do not run away.” In some languages an expression for bravery may seem almost contradictory to our own ways of thinking; for example, for a person to be brave is in some languages “to have a hard heart” or even “to have a heart like stone.”

The verb defeated is used only here in the Gospel of John, but note its use in 1 John 2.13-14; 4.4; 5.4-5. Both Paul (1 Cor 15.57) and the author of Revelation (5.5; 6.2; and 17.14) speak of Jesus as the one who defeats the world and so gives victory to his followers. In some languages have defeated would be rendered “have won the battle against” or “have been successful in fighting against.” This figure of speech is probably acceptable, provided one does not use as an object of the verb such a rendering as “the people of the world.” Though in many contexts the world may be rendered “the people of the world,” in this particular instance John is emphasizing not Jesus’ victory over people, but over the world force, or the system of the world. The only equivalent in some languages would be “the power of this world.” However, in order to speak of “defeating the power of this world,” it may be necessary to say “I have destroyed the power of this world.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .