Jesus said to his disciples:
“I am the true vine, and my Father is the gardener. He cuts off every branch in me that bears no fruit, while every branch that does bear fruit he prunes so that it will be even more fruitful.
Jesus drew an apt analogy here. Both grape vines and people inherently need pruning.
That’s certainly true of grape vines. “If left unattended, grapevines can become unruly, and fruiting will be poor due to overproduction of vegetation.” Basic Principles of Pruning Backyard Grapevines (Ohio St. Univ. Extension 2004).
It’s also true of us. People left to their own will inevitably sin and hence be less fruitful than they could be. We see that throughout scripture. Genesis 6:5 and 8:21 tell us that “every inclination of the human heart is evil[.]”1 John 1:8 tells us that if “we say we have no sin, we deceive ourselves[.]” Proverbs 29:15, John 7:8-9 and Romans 3:23 also recognize that reality. That is even true of Godly folks. Think about Abraham in Genesis 12:10-20 and Genesis 20 and Paul in Romans 7:8-24. We are inevitably less than we can be without God’s pruning.
But what about the argument that even atheists can do good things? That is true enough, but doesn’t go far enough. There is no denying that many people with no relationship to Jesus do great good, but are they doing as much good as they could if they moved in His strength by moving according to His will? Probably not. Instead, they are like untrimmed grape vines. They bear some, but not as much, fruit as they would if they were powered—and pruned—by Jesus.