Big idea: You reap what you sow.
When I taught High School, kids always asked variations of the same question when it came time for finals. Someone with a competitive GPA wanted to know what they needed to make to get an A. Of course, more of them asked, "What do I need to pass?" The question is always the threshold. How little can I do to stay out of trouble? In some places, this attitude is not harmful. No one wants to go into the car dealership and ask how much they can pay for a car. You want to get out of there with the minimum for what you want. Software engineers talk about the MVP - the Minimum Viable Product. How little will get the job done, so we can make sure we do the core first and the frills later?
But this attitude is much less apropos for the Christian life. The issue should not be how little we can do or how little we can give to appease God, as if He were the IRS and we were maximizing our refund. No, the Christian life is much more like farming. You could calculate the minimum you need to plant to support your family or you could realize that the more you plant, the more you will harvest. Then the question is not, "How little can I do?" Instead, you begin asking, "How much can I do?" If we believe that God is the source of all we have and He is able to multiply it, we should want to push the limits of what we can share.
The challenge Paul issues the Corinthians is to realize that while they will sow physical things, the harvest will be much greater. Their generosity will spur others to generosity. their gift will reach the lost and encourage the saved. Most importantly, when they planted money, they would harvest praise for God. Their own praise when they learned that God still provided for their every need and the praise of others reached by their generosity would both resound through eternity. If generosity with time and treasure yields something so precious, could we ever ask, "What must I do?" No, we must always look for opportunities to be the cheerful givers that God loves.
Discussion idea: What is your automatic attitude when giving? How could you improve it?
Prayer focus: Thank God for the person who shared the gospel with you. Were you saved at a church, a camp, by TV, radio, or tract? If your experience was something like that, thank God specifically for the generosity of those who made those ministries possible.