NOTES for Co1 1:17
In the early Christian Church there were different ministries to which God called different people. One of these ministries was the ministry of an apostle, or messenger, which existed not only in the Church but also in other Jewish religious brotherhoods of the Gospel era, on whose model the early Christian Church was formed.
For religious brotherhoods the ministry of messengers always had special importance, since these were communities without a rigid structure, more like communal movements than centralized organizations. Messengers played an important connecting role in such movements: they could testify to members of other communities about important events, both communal and spiritual, that were happening in their own community. In this way the brotherhoods exchanged spiritual and life experience, without which the brotherhood could not exist as a single whole.
In the Church, however, the role of the apostle-messenger had special importance, because the Church was held together first of all by the good news and by testimony. The Church was not a religious organization bound, as usually happens in religious organizations, by a single ritual or a single doctrine. Of course, most members of the early Christian Church were connected with the Synagogue, but the Synagogue was not unified in this respect either, all the more since the Church included not only Jews but also recent pagans who were interested in Judaism without fully accepting it, and for them Jewish ritual was not as close and organic as it was for the Jews themselves.
The early Christian Church was united only by faith in Jesus as the Messiah promised by God, whom God had raised from the dead, and in the Kingdom that this risen Messiah brought into the world and to which everyone who believes the risen Jesus and entrusts his life to Him can be joined. Here testimony about the Risen One and about the Kingdom He brought into the world came to the forefront, and apostolic ministry became central.
Paul is therefore glad that it was precisely apostolic ministry that was entrusted to him by God. Of course, Paul did not have a church that he could call his own in the sense in which those who headed specific church communities called different churches their own. But this state of affairs did not upset him at all, for he understood what ministry had been entrusted to him by God.