Why was grace the only thing that could reach the wicked Corinthians?
Because the Corinthians were wracked with immorality and fully immersed in a society that accepted it, no other approach could succeed. Only by grace did God begin to save these wicked Corinthians; anything apart from grace would have failed entirely.
Les teaches that into Corinth—a city wracked with immorality—Paul came with the gospel of the grace of God. Since anything but grace would never have succeeded, it was only by grace that God began to save these wicked Corinthians. Les also compares spiritual life to physical life: believers are born into God’s family as babes in Christ, not mature, so failures can occur, just as infants must grow.