How do we reconcile our disappointment in “unanswered” prayer with our belief in an all-knowing God?

How do we reconcile our disappointment in “unanswered” prayer with our belief in an all-knowing God?
God grants us freedom to rebel against his original design, yet even as we do so, we end up ironically serving his eventual goal of restoration.
God’s “the inner voice of love,” is precious indwelling reminder that frees us to act as God’s beloved, beyond the reach of human praise or blame.
When Jesus said, “unless you change and become like little children, you will never enter the kingdom of heaven,” what did he mean?