1 Peter 4:19

‘Wherefore let them also that suffer according to the will of God commit their souls in well-doing unto a faithful Creator.'

Believers suffer in order that they might be purified and cleansed. Thus their suffering is in the will of God. It is because He is working in them to will and to do of His good pleasure (Philippians 2:13). And as a result, in their sufferings, they can commit their whole beings to Him as One Who is a faithful Creator, in the same way as in His sufferings Jesus committed His spirit to Him as His Father (Luke 23:46; compare also the Psalmist in Psalms 31:5). And they do it by themselves doing good and revealing Christlikeness towards their enemies, for they are His workmanship, created in Christ Jesus unto good works, which God has foreordained that they should walk in them (Ephesians 2:10). God's creative work is at work within them and is coming towards its conclusion in their being made ‘perfect and complete in all the will of God' (Colossians 4:12) and their revealing it in the world.

This idea that God's creative work is coming to its fulfilment through the bringing of His creations to Christlikeness through suffering is a reminder that God's creative work, while in one way complete (Genesis 1:31 to Genesis 2:3), is still in another way in progress. In other words history has not just been a sad accident. It has all been a part of His bringing His elect to Christlikeness through suffering in accordance with His purposes.

So those who are elect according to the foreknowledge of God the Father, by sanctification in the Spirit, are being brought to the obedience of Jesus Christ as a result of the sprinkling of His blood (1 Peter 1:1), and their partaking with Him in His sufferings (1 Peter 1:7; 1 Peter 4:1), through which they are brought to God (1 Peter 3:18), so that they may live unto righteousness (1 Peter 2:20). Out of seeming judgment will come ultimate victory and triumph.

It is possible that Peter has in mind here 2 Samuel 22:31 LXX, ‘As for the Mighty One, His way is blameless. The word of the Lord is strong  and tried in the fire. He is a protector to all who put their trust in Him. Who is strong, but the Lord? and Who will be  a Creator  except our God? It is the Mighty One who strengthens me with might, and has prepared my way without fault.' In these words also we have mentioned the trial by fire for those involved in the going forth of His word, combined with the idea of the protection of God our Creator (Greek: Creator; Hebrew: Rock), the only use of the word in the Greek Old Testament. This usage in 2 Samuel suggests that behind the word ‘Creator' is the idea of One Who is mighty and powerful, and totally dependable in the faultless way which we have to take.