In 10:12-18, Paul talks about his and Timothy’s “sphere” which God apportioned to them, meaning the sphere of gospel influence. Corinth was in the sphere of Paul and Timothy’s gospel influence apportioned to them by God, which is why God allowed them to go there preaching the gospel.
In 10:15-16, Paul expresses the hope that their sphere would increase so they could proclaim the gospel in regions beyond Corinth.
“but with the hope that as your faith grows, we will be, within our sphere, enlarged even more by you, so as to preach the gospel even to the regions beyond you...”
Paul sees a direct connection between the increasing faith of the Corinthians and the enlargement of his and Timothy’s sphere of gospel influence. As the faith of the Corinthians grows, so grows the area where Paul and Timothy could proclaim the gospel. The quality of faith of the Corinthians reflected the quality of work done by Paul and Timothy. As Paul and Timothy labored to build them up in their faith, they were being faithful with what God had given them. They were faithful with what God had given them, expecting God to give them more.
What are the implications of this?
Does the ability to move forward into future work depend on what you do in the present work God gives you?
I think so. The parable in Luke 19:11-27 speaks to this; those who were faithful with small things (a few coins) were given responsibility over greater things (cities).
If there is a future place you want to go, or people you want to work with, or ministry you want to be involved in, do the best possible job you can do here and now, expecting the Lord to reward you with opportunities in what you hope to do in the future.
We tend to be afraid to commit ourselves to something here and now when our hearts want to be somewhere else. We think that if we commit, this commitment will somehow hinder us from going where we want to go. Or even worse, we will begin to be content with being here. But the kingdom of God does not work like this.
Paul and Timothy were fully invested in the building up of the faith of the Corinthians, and they fully expected God to increase their sphere of gospel influence in proportion to work they did among the Corinthians.
The Lord expects us to work diligently in whatever work He gives us to do, being fully invested in that time and place where He has us at the present moment. Trust Him with your future, and work hard in the present to see His kingdom come. Disciple others as if they will be the last people you ever disciple. Be fully invested in the here and now, and be willing to move on when He opens the door for you to do so. Trust Him with your desires for the future, and obey Him here and now.
And when you have done all the Lord asks of you to do here and now, He will reward you with more opportunities to be faithful to Him among other people or places.