Charles H. Spurgeon on Psalms 130:4

But there is forgiveness with thee. Blessed but. Free, full, sovereign pardon is in the hand of the great King: it is his prerogative to forgive, and he delights to exercise it. Because his nature is mercy, and because he has provided a sacrifice for sin, therefore forgiveness is with him for all that come to him confessing their sins. The power of pardon is permanently resident with God: he has forgiveness ready to his hand at this instant. "That thou mayest be feared." This is the fruitful root of piety. None fear the Lord like those who have experienced his forgiving love. Gratitude for pardon produces far more fear and reverence of God than all the dread which is inspired by punishment. If the Lord were to execute justice upon all, there would be none left to fear him; if all were under apprehension of his deserved wrath, despair would harden them against fearing him: it is grace which leads the way to a holy regard of God, and a fear of grieving him.