Opening Greeting (2 Corinthians 1:1-2).
‘Paul, an apostle of Christ Jesus through the will of God, and Timothy our brother, to the church of God which is at Corinth, with all the saints who are in the whole of Achaia.'
Having again established his reputation in Corinth Paul addresses the believers as ‘an apostle of Christ Jesus through the will of God.' He is, he says, a directly God-appointed ‘Apostle of Christ Jesus', chosen as such from birth and called by God in accordance with His will (Galatians 1:15). For a similar greeting compare Ephesians 1:1; Colossians 1:1; 1Ti 1:1; 2 Timothy 1:1. It is noteworthy that when he includes others in his greeting, and he does not separately cite the fact that he is an Apostle, no title is ever used, unless we consider the word ‘bondmen' (douloi) (Philippians 1:1) to be a title. Apostleship was unique, and gave unique authority. The others were ‘brothers'.
This introduction in 2 Corinthians was a fairly standard introduction, and did not introduce any special further comment. He clearly felt that it was all that needed to be said. Later in the letter he will defend his right to the title to the hilt, but it seems that he did not feel it necessary at this stage.
‘An Apostle of Jesus Christ.' This phrase primarily, of course, referred to the Apostles appointed by Jesus (and named ‘Apostles' by Jesus - Luke 6:13), ‘the twelve' (John 20:24; Acts 6:2; 1 Corinthians 15:5), who had directly received revelation from Jesus and were witnesses of the resurrection (Acts 1:22; 1 Corinthians 15:5). They had come to include James the Lord's brother (Galatians 1:19), who possibly replaced the martyred James (Acts 12:2 with Galatians 2:9) as Matthias replaced Judas (Acts 1:10-26).
In Acts the twelve are clearly distinguished as unique. When writing about those who met in the Jerusalem church to make vital decisions, the leaders apart from the Apostles are called ‘the elders', and the Apostles are mentioned separately. Note the phrase ‘the Apostles and the Elders' (e.g. Acts 15:2; Acts 15:4; Acts 15:9; Acts 15:22-23), even though the Apostles could also be called Elders (1Pe 5:1; 2 John 1:1; 3 John 1:1). The ‘Elders' are those usually responsible for churches (Acts 14:23; Acts 20:17). Thus Paul, by calling himself an Apostle here, sets himself alongside the twelve as having this unique position. Like them he too claimed to be a primary source of direct revelation from Jesus Christ (Galatians 1:12), and was recognised as such by the twelve (Galatians 2:7-9). And it is clear that he looked on his calling to Apostleship (Romans 11:13; 1 Corinthians 9:1) as being on a par with, and as personal as, theirs (Galatians 1:16-17).
‘Apostolos', an apostle, is derived from apostellein, (to send forth,) and originally signified literally a messenger. The term was employed by earlier classical writers to denote the commander of an expedition, or a delegate, or an ambassador (see Herodotus, 5. 38), but its use in this way was later rare as it came to have a technical meaning referring to ‘the fleet', and possibly also the fleet's admiral. It may be that Jesus spoke with a sense of humour when he named the fishermen ‘Apostles' using this term, seeing them as the future ‘catchers of men' (although it would require that He gave the title in Greek. This is not, however, impossible. They were bi-lingual).
In the New Testament, apart from its use of the Apostles, it is also employed in a more general non-technical sense to denote important messengers sent out by churches on God's service (see Luke 11:49; 2 Corinthians 8:23; Philippians 2:25; 1 Thessalonians 2:6), but presumably the only authority it then gives is their authority as messengers of whoever sent them, and it is nowhere suggested that it is permanent. And in one instance it is applied to Christ Himself, as the One sent forth from God (Hebrews 3:1). But in the main it is reserved for the twelve (including James, the Lord's brother), and Paul and Barnabas (Acts 14:4; Acts 14:14). Paul certainly saw it as giving him a recognised authority direct from Jesus Christ. He saw himself, along with the twelve, as being specifically and personally commissioned by Jesus.
‘Through the will of God.' This solemn statement stresses the importance of his office. He declares that it is through the sovereign will of the eternal God that he has been so appointed. He is deliberately emphasising that he was called as an Apostle by the direct will and purpose of God, so underlining that he has been chosen out within God's specific purposes. He no doubt intended them to see this as being evidenced by his experience on the Road to Damascus, where God had set him apart in a unique way through the appearance to him of the resurrected Lord Jesus Christ, calling him to a unique ministry among the Gentiles. He wanted them to know that he spoke with maximum authority.
But in the light of what comes later in the letter we may probably also see this ‘through the will of God' as in direct contrast to those who ‘transformed themselves into the Apostles of Christ' (2 Corinthians 11:13), those who ‘call themselves Apostles and are not' (Revelation 2:2), appointed by themselves and not by the will of God. He wants to stress that, in contrast to theirs, his Apostleship is through the will of God.
With him in his greeting he includes Timothy, who is with him at the time, who is simply ‘our brother'. This mention was because they knew of Timothy from an earlier letter (1 Corinthians 16:10), and, if his proposed visit had ever taken place, actually knew him personally. It also had the purpose of establishing Timothy as one who worked with him and could be relied on. The intention was that it would give him authority if ever he again went to Corinth on Paul's behalf.
‘To the church of God which is at Corinth.' This covers all the Christians in Corinth no matter which gathering they attended. The ‘church' is the sum of the believers. ‘Church of God' is equivalent to ‘all the saints (sanctified ones)'. That it is ‘of God' confirms that they are seen as belonging to God and therefore ‘sanctified' (set apart for a holy purpose) to Him (1 Corinthians 1:2).
‘With all the saints who are in the whole of Achaia.' The letter is intended to go throughout Achaia. This was probably intended to indicate a local area around Corinth, based on ancient usage, rather than the larger Achaia of Paul's day. The ancient usage was probably preserved in the area itself as such usages tend to be. The title ‘saints' is taken from the Old Testament (e.g. Deuteronomy 33:3; 1 Samuel 2:9; 2 Chronicles 6:41; Psalms (20 times); Daniel (4 times)) and confirms that the church was seen as the new Israel (compare Galatians 6:16; Ephesians 2:12-22; Romans 11:13-24). God's people are God's ‘holy ones', God's separated ones, sanctified (set apart for God) in Christ Jesus (see 1 Corinthians 1:2).