Whom resist stedfast in the faith, knowing that the same afflictions are accomplished in your brethren that are in the world. Whom resist - Stand against him, αντιστητε. Though invulnerable, he is not unconquerable: the weakest follower of God can confound and overpower him, if he continue steadfast in the faith - believing on the Son of God, and walking uprightly before him. To a soul thus engaged he can do no damage.
The same afflictions are accomplished in your brethren - It is the lot of all the disciples of Christ to suffer persecution. The brotherhood, αδελφοτης, the Christian Church, everywhere is exposed to the assaults of men and devils; you are persecuted by the heathen among whom ye live, and from among whom ye are gathered into the fold of Christ: but even those who profess the same faith with you, and who are resident among the Jews, (for so I think εν κοσμῳ, in the world, is here to be understood), are also persecuted, both heathens and Jews being equally opposed to the pure and holy doctrines of the Gospel. Any man who has read the Greek Testament with any attention must have observed a vast number of places in which the word κοσμος, which we translate world, means the Jewish people and the Jewish state, and nothing else.