In Matthew 7:1-5, Jesus tells us that we should not judge one another. To follow this command is to acknowledge the God is the only true Judge, and recognizes that we are all equally sinful and deserving of God's judgment. Apart from God's grace, we have no hope. So rather than point out other's mistakes and failures, we ought to humbly acknowledge our own and allow God to heal us. If we do take the "plank" out of our own eye, God can use that "lumber" to build something good for others in the way of empathy and kind instruction.