Albert Barnes on John 16:33

In me. In my presence, and in the aid which I shall render you by the Holy Spirit.

In the world. Among the men to whom you are going. You must expect to be persecuted, afflicted, tormented.

I have overcome the world. He overcame the prince of this world by his death, Jn 12:31. He vanquished the great foe of man, and triumphed over all that would work our ruin. He brought down aid and strength from above by his death; and by procuring for us the friendship of God and the influence of the Spirit; by his own instructions and example; by revealing to us the glories of heaven, and opening our eyes to see the excellence of heavenly things, he has furnished us with the means of overcoming all our enemies, and of triumphing in all our temptations. Jn 14:19; Rom 8:34, also Rom 8:35-37, 1Jn 4:4, 1Jn 5:4, Rev 12:11. Luther said of this verse "that it was worthy to be carried from Rome to Jerusalem upon one's knees." The world is a vanquished enemy; Satan is a humbled foe; and all that believers have to do is to put their trust in the Captain of their salvation, putting on the whole armour of God, assured that the victory is theirs, and that the church shall yet shine forth fair as the moon, clear as the sun, and terrible as an army with banners, Song 6:10.

(a) "in me you might have peace" Jn 14:27, Rom 5:1, Eph 2:14 (b) "In the world" Jn 15:19-21, 2Ti 3:12