The Bible compares our spiritual lives to living, growing things: we are like trees planted beside streams of water. Time and time again, Jesus compares the kingdom of heaven to living, growing things: a mustard plant, a farmer planting seeds, a field of grain. And, he teaches us, it's by the fruit that you know the tree.
It wasn't until after I started gardening that I realized: a lot of plants never bear fruit if you plant them alone. One blueberry bush won't do you much good, or one pecan tree, or one corn plant. One plant by itself might not produce much: in fact, it might not produce at all, if there isn't another to cross-pollinate. For corn, you do best with rows and rows, all close enough that they catch the pollen blowing in the wind from each other.
That's a little bit what church is like, and Bible studies. Everything that brings us together as Christians makes us more fruitful, more productive. In the Bible, Paul famously listed the kinds of "fruit" of a spirit-filled life: love, joy, peace, patience, kindness, goodness, faithfulness, humility, and self-control. How can a Christian grow in love, or produce love, alone? Love by its very nature is connected to another. (Given that love is good, it follows that "It is not good for man to be alone.")
If you don't mind me being a little playful, we could almost look at congregations of believers in churches -- seated in pew after pew after pew -- as row crops. And once we're pollinated, we go back to our homes and jobs to bear fruit of love, joy, peace, patience, kindness, goodness, faithfulness, humility, and self-control. And maybe, just maybe, when we bear fruit -- another seed will be planted.