One reason, amongst many, is to teach our souls to delight in grace. Like a thirsty palate washed with sweet water, grace is only beautiful to those who know they need it. Unfortunately, our pride causes us to see sin lightly. This is why the heresy of universalism is so prevalent today (the idea that God saves all people in the end, because it is unjust for Him to punish people eternally for finite sins). People who propound this heresy are (ironically) people who do not know grace, and they do not know grace because they do not know their own sin.
For the Christian, sin is an ever-increasing reality in their lives. Not because they sin more – the opposite is true – but because they become more and more aware of its presence in their lives. Like an exterminator that did not notice the rats in the attic, but sees more and more of them the deeper he goes and the more he kills.
God, in His grace, allows us to fall time and time again, so that we might know the beauty of His embrace as He picks us up. The child who stumbles the most, often has her hand most tightly in the Father’s. The more we taste God’s grace forgiving our sin, the sweeter it becomes because we get to know all of its intricate delicacies. Wine connoisseurs learn about the wonderful tastes of wine because they drink it time and time again. A child would think wine is spoiled grape juice, but a sommelier knows each and every flavor – dozens of them. Like this, the Christian life is partly one in which we constantly enjoy God’s grace, tasting it afresh each morning.
Of course, this does not mean we deliberately sin so that His grace may abound (Rom. 6:1-2). This is as foolish as the sommelier becoming wine-drunk – his senses are dulled and he can no longer enjoy the beauty of the wine. The beauty of God’s grace is only seen when it is held in contrast to the utter horrors of sin. You cannot appreciate one without the other.
So, we flee from sin, constantly falling, because God’s grace gives us the power to do so. The faster we run, the more grace we need, and the more grace we get, the faster we run. If you struggle with sin, know you are just like the rest of us. Use your struggle as an opportunity to drink deeply from the bottomless well of God’s abundant grace. The more you start to understand the beauty of His grace, the less you will sin. This is the way our loving Father guides us out of the house of death – not with threats, but with promises.