‘Do all things without murmurings and questionings, that you may become blameless and harmless, children of God without blemish in the midst of a crooked and perverse generation, among whom you are seen as lights in the world,'
And part of the working out of this salvation would be that it would result in unity among themselves, so that all murmuring and questioning was done away. This is not so much referring to questioning the truth about things, but to the questioning of other people's faith, purposes and motives. We could translate as ‘disputes and quarrels'. Here we get back to what has up to now been a theme of the letter, the desire for them to walk in unity and love (Philippians 1:9; Philippians 1:27; Philippians 2:1-4; compare Philippians 4:2), and it will be brought about by their fulfilling the injunctions of Philippians 2:5 and Philippians 2:12.
The importance of this unity and love comes out in that this is to form a large part of their presenting a blameless front to the world at which no finger can be pointed. The word rendered blameless was used in LXX in Genesis 17:1. where Abraham was commanded to be blameless, and of Job in Job 1:1; Job 1:8; Job 2:3 where we learn that Job was a blameless man, even in God's eyes. Both lived their lives by faith with a view to pleasing God (Genesis 15:6; Job 1:1; Job 13:15; Hebrews 11:8-10). Furthermore they were to be ‘harmless'. In other words they must be make clearly apparent that they are not ‘causers of harm' (are harmless as doves - Matthew 10:16), and that they are truly children of God undeserving of rebuke, before a world outside which is both crooked and perverse. Indeed it will make them lights in the world as they shine out before their fellow-men (compare Matthew 5:16; John 8:12). The word rendered harmless can also mean ‘undiluted', containing the thought that they are to be pure through and through.
‘Without blemish.' Comparison with Philippians 2:18 may suggest that here Paul has in mind the unblemished lamb which was offered for sacrifice (1 Peter 1:19), with the thought that even though they are lights in the world, it will not prevent their being offered up as a sacrifice to God by their persecutors. It was precisely the unblemished lamb that was offered up. Being without blemish was also God's aim in choosing them out for Himself (Ephesians 1:4), and it was as those who were without blemish that they would be presented to Christ as His bride-wife (Ephesians 5:25-27).
In contrast the unbelievers are ‘crooked (not straight, unscrupulous, dishonest) and perverse (depraved)'. Their lives are questionable at every point, even when they appear to be doing good. And this includes the Jews who have rejected Christ and have therefore been cut out of Israel, being replaced by Gentile converts (Romans 11:17-28).
The combination of the ideas ‘children of God -- blameless -- without blemish -- crooked and perverse generation' may suggest that Paul has Deuteronomy 32:5 in mind. ‘They have dealt corruptly with Him, they are not His children because of their blemish, a perverse and crooked generation'. Thus the Philippians are to demonstrate that they themselves ARE His children as is to be evidenced by their unblemished lives in contrast with those who demonstrate that they belong to a crooked and perverse generation. It is the church who are to be revealed as the true Israel, the true children of God