Unity
We have seen that Paul encourages the members in Corinth to get involved in a collection for the impoverished churches in Judea. One of his purposes is to kindle a sense of unity. He wants them to participate, to be part of the mission. He wants to show that the Gentile churches are part of the same family of God as are the Jewish believers in Jerusalem. That is, these people, who were once their opponents, are now, indeed, fellow members with them in God's New Covenant remnant. Paul wants to see the whole Christian family, Jew and Gentile, united in a powerful way that can bear a witness to the church in generations to come.
Titus and two other acclaimed brothers were in charge of the funds. God put this care for the church into the heart of Titus (2 Cor. 8:16). Through the churches, God also chose the two other brothers (2 Cor. 8:18-23). They are called "messengers of the churches, the glory of Christ" (2 Cor. 8:23, NKJV). Whether "the glory of Christ" describes these two faithful brothers or the churches themselves does not matter. Giving offerings is ultimately a signal of loyalty to Christ, the Head of the church (Eph. 4:15).
Second Corinthians 8-9 indicates that the offerings should be given to people appointed by God through the church. The phrases "all the churches" (2 Cor. 8:18, NKJV), "chosen by the churches" (2 Cor. 8:19, NKJV), and "messengers of the churches" (2 Cor. 8:23, NKJV) suggest precisely that. Thus, the following exhortation is not surprising, "Give proof before the churches of your love" (2 Cor. 8:24, ESV).
Bringing offerings to the church--God's appointed instrument on earth--promotes unity and, at the same time, is the result of a sense of unity (2 Cor. 8:13-14). Money can be a great unifier. On the other hand, if people's eyes are not single to the glory of God, money can create division as well.
How does Romans 15:26-27 reveal Paul's desire for unity here?
Finally, Paul depicts the collection as service or ministry, as an act of grace, as a blessing, as an act of worship, and also as fellowship. All that from an offering? Think about it.
How does our giving to fellow churches and missions overseas, often in faraway places, help bring unity to our world church?