‘Only let your manner of life as citizens be worthy of the gospel of Christ, that, whether I come and see you or be absent, I may hear of your state, that you stand fast in one Spirit, with one soul striving for the faith of the gospel.'
In the light of what they already know about Christ, and what he is shortly to describe to them concerning Him in some depth (Philippians 2:5-11), he calls on them to ‘live as citizens' (politeuesthai), worthy of the Good News of Christ (the Good News that they can partake in His death and resurrection). For just as Philippi was a ‘colony' of Rome, being seen as a kind of adjunct of Rome (see introduction), so the Philippian church were to see themselves as a colony of Heaven (Philippians 3:20), and thus living in a kind of adjunct of Heaven. They were therefore to live accordingly, especially in the light of the example of the One to Whom they looked, the One Who was God's ‘good news' (Gospel) to mankind (compare Luke 2:10-11) and was now the LORD in Heaven (Philippians 2:11). And this included their standing fast in one Spirit, striving together as one for the whole message of the Gospel. And they were to do this regardless of whether he was able to visit them or not, as they had in the past (Philippians 1:5), for it was to be the very mainspring of their lives.
‘That you stand fast, striving for the faith of the Gospel.' The language is that of the arena, as the gladiator stands firm in the face of his opponent and then strives to obtain the mastery, or of the battlefield where the stout warrior does the same. In the same way they are to stand firm (Ephesians 6:14-17) and strive for the success of the truth of the Gospel (compare Ephesians 6:10-12; 2 Timothy 2:3-5). that Gospel through which they had received forgiveness and life in Christ.
That the reference to ‘standing fast in one Spirit' is to the Holy Spirit, and not simply to their own spirit, is suggested by the fact that this ‘oneness in the one Spirit' is a continual theme of Paul's. It is the Holy Spirit who unites us as one in Christ (1 Corinthians 12:13), and we are one because participating in the One Spirit. See for example Philippians 2:1; 1 Corinthians 12:13-27; Ephesians 2:18; Ephesians 4:4. It must, however, be acknowledged that such a unity of the Spirit does inevitably result in a unified spirit among believers, an idea expressed here in terms of ‘one soul'. We may see the ‘spirit' as being that in man which experiences and is aware of God, while seeing the ‘soul, life' as representing his inner being and personality. But here the distinction blurs, for it is also with the inner being (‘the soul') that we know God and strive for the faith of the Gospel. As elsewhere, spirit and soul both ‘inter-connect', and with the body make up the whole man (1 Thessalonians 5:23). But we must beware of making too much of a distinction between these descriptions, for they are not separable, but merge into one another making up one man (compare how Jesus could speak of a quadruple ‘heart, soul, strength and mind' - Luke 10:27, which compared with 1 Thessalonians 5:23 might be seen as indicating that ‘spirit' equates with ‘heart and mind', something which however must not be overpressed, just as ‘strength' is not limited to the body).
‘The faith of the Gospel' probably refers to the content of the Gospel, centring in the suffering, death and resurrection of our Lord Jesus Christ, not, however, as a cold doctrinal formula, but as a part of their living faith, vibrantly believed. It could, however, equally indicate the faith that results from the Gospel. Both in fact intertwine.