Knowledge has limits. There are many things we do not know. It is a sign of wisdom and understanding to acknowledge our limits.
Not only are do we as individuals have limits but mankind has limits. We are not unlimited in our ability to understand. We cannot know the mind of God or many hidden things.
We see often through a glass darkly. We seek knowledge of God but often we must admit our knowledge is partial and incomplete.
We need the humility in life to acknowledge our limits. It is often why we do not know what to pray. We think we know what is right but often we are too limited to see the big picture.
We often ask why God did not respond as we wish, but we should ask why we doubt the wisdom of the eternal all powerful God.