1 Peter 5:9

‘Whom withstand steadfast in your faith, knowing that the same sufferings are accomplished in your brothers who are in the world.'

Resisting the Devil is a concept also found in Ephesians 6:11; James 4:6. In the former case it is by faith in God through His word, and in the latter case it is by humility, submission to God and faith, as here. In Ephesians 6 it is expanded in terms of being clothed in the armour of God, in other words it is through trust in God's word and promises, so again by faith. Jude stresses how necessary it is to depend on the Lord totally in dealing with Satan (Jude 1:9). According to Jude it is the foolish who treat him lightly (Jude 1:8; Jude 1:10). We must deal with him in the Lord's strength.

And as they make their stand against persecution they are to recognise that all their brothers who are still in the world are subject to similar persecution. Only the saints in glory (1 Peter 4:6), who are not in the world, escape it. Thus it is confirmed that it is ‘no strange thing' that is happening to them (1 Peter 4:12) for it happens to God's people everywhere. This may suggest that some had panicked when persecution arose, feeling that it contradicted the onward march of the Gospel of Christ. Unlike the Jews they were not used to it.

‘In your faith.' The question often raised with regard to this is whether it is their personal faith that is in mind or the body of faith that has been preserved by the churches. Whichever it is it really means the same. Peter would not have exhorted them to any other kind of faith than faith in God and His promises, and that would be faith in ‘the faith'. And being steadfast in the faith would necessarily indicate being steadfast in personal faith.