Given perfect knowledge, we could (and, I must believe, would) be perfectly virtuous.
Even the greatest desire has no power over understanding. This is why wisdom -
glimpses of Truth - is the only path to consistently
virtuous action, but it is fleeting in this world, and hard-won at the best of times.
We must err to learn the edges of the path that we are to follow.
In this respect we are like blind wanderers, seeking an exit from a catacomb. We are surrounded by death and charnel, which we know only by the most gruesome and unexpected contact with it. Even when the way before us is clear, our battered, trembling fingers expect to encounter only rough, cold stone. Our feet stumble forward, and the least obstacle causes us to fall, sometimes catastrophically. When we encounter a true companion, it is the most joyous thing in the world, for if we are to be blind, at least we need not be alone.
God, who fashioned dungeon and prisoners alike, beholds the entire spectacle, and waits to pass His judgment.