‘For which reason, my brothers, beloved and longed for, my joy and crown, so stand fast in the Lord, my beloved.'
‘For which reason.' This means, ‘Because of what I have just been saying, and because of what is in the whole of this letter --.' Paul then follows this by stressing his deep affection for them as he puts his whole heart into calling on them to ‘stand fast in the Lord'. The affection is emphasised in a fourfold way, ‘my brothers (and sisters)', ‘beloved and longed for', my joy and crown', --- ‘my beloved'. He is holding nothing back. It is quite clear that the Philippians were very close to his heart, and that he thus wanted the very best for them.
‘My brothers and sisters.' The word adelphoi, while masculine, was inclusive of both male and female Christians. It was a term which indicated the close tie that he felt for his fellow-believers. They were united with him in one Spirit, and together with him were ‘in Christ', made one by participation in His body (1 Corinthians 12:12-27). They were his kin in Christ (Galatians 3:28), with Jesus in His humanity as their elder brother (Hebrews 1:11-14). And as such he loved them.
‘Beloved and longed for.' He had described them as beloved in Philippians 2:12, and had spoken of his longing to be with them once again, and for their spiritual growth, in Philippians 1:8 (compare Philippians 1:7 ‘and have you in my heart'). And it was this that moved him to pray so earnestly for their spiritual wellbeing (Philippians 1:9-11). Furthermore it was a love that he wanted them also to have for each other (Philippians 2:2).
‘My joy and crown.' We must not see this as simply indicating Paul's hope that he would receive recognition and applause for himself on the day of judgment because they were his trophies. He did not see it like that. Rather he saw them as coming with him into the Lord's presence daily (as he lifted them up before God) as his cause for joy, and as the crown on his work for God. As he prayed they were the cause of his joy, and the crown on his prayers. For he is delighting in the fact that they are at present ‘his joy' as he approaches the Lord, and as he enters in prayer and praise for them into the presence of the Lord, and are the crown on his ministry, the extra garnish which gives it extra taste, as they come in triumph together. And he rejoices that ‘in that Day' he will also be able to joy in them and ‘show them off', as they too enjoy the blessing of the Day (see 1 Thessalonians 2:19). They will be there with him as evidences of the Lord's triumphant work (Philippians 1:6; Philippians 2:13). They will be his cause for rejoicing because of the steadfastness of their faith, and they will be his crown because he sees them as coming with him into the presence of the Lord, acting as a seal on God's activity through his ministry, adding to the glory that comes to the Lord as a result of it. They were the present proof that he had indeed not run in vain, and were the guarantee of the genuineness of God's work through him. And in the future when he came before God's judgment seat he would joy in them and as it were ‘wear' them (by their presence along with him) as a token of the Lord's victory through him, so that God might be glorified, and they might all be blessed.
‘My beloved.' Note the twice repeated beloved. He yearns for them to recognise the love that he has for them.
And because of his love for them he wants them to ‘stand fast in the Lord.' ‘In/by the Lord' could indicate standing fast along with Him, in His strength (Ephesians 1:19; Ephesians 3:16-17), or their standing fast because they are one with each other and with Him ‘within the sphere of Christ' (in Christ). But if we take the latter meaning we must not overlook that fact that to be ‘in the Lord' (or ‘in Christ'), is to be as closely united with Him as it is possible to be (‘Your life is hid with Christ in God' - Colossians 3:3). Standing fast has in mind their opponents, both spiritual (Satan and his minions - Ephesians 6:10-18) and physical (including worldly persecutors and heretical teachers). He is not promising that life will be easy, only victorious if they are truly ‘in the Lord'.
There is a reminder here that we are in a warfare during which we often have to plant our feet firmly and stand up to what is thrown against us (compare 1 Corinthians 16:13). There is no promise that being a Christian will be easy, rather the opposite. But as Paul makes clear, at such times we are never alone. We stand fast ‘in the LORD'. And we are provided with the wherewithal to stand (Ephesians 6:10-18). And this standing fast also includes standing fast against false teaching, and holding firmly to the truth (Galatians 5:1; 2 Thessalonians 2:15), which in view of chapter 3 may well be in mind here.