What does Psalm 18:11 mean?

Adding to his description of how the Lord delivered him from enemies such as Saul, David writes that the Lord covered Himself with darkness like thick rain clouds. Invisible to the human eye, the Lord was working out His purpose to rescue David. We cannot see God, but the eye of faith perceives that He has a purpose for our lives. Romans 8:28 assures us that all things, including hard trials, work together for good for those who love God and are called according to His purpose.

Joseph, a major figure in the Old Testament, is a classic example of how God works behind the scenes. God's purpose for Joseph was to put him in high command in Egypt so he would save the lives of God's chosen people. When a severe famine struck that part of the world (Genesis 41:53–54), Joseph had already counseled the Egyptians to store grain in the years of bountiful harvest so it would be available in the lean years (Genesis 41:46–49). His wise plan kept the descendants of Jacob alive when they came to Egypt in search of grain (Genesis 42:1–3). Later Joseph reflected on his brothers' malicious treatment of him that had taken him from Canaan to Egypt (Genesis 37:23–28). Joseph remarked, "As for you, you meant evil against me, but God meant it for good, to bring it about that many people should be kept alive, as they are today" (Genesis 50:20). The Lord works in secret, mysterious ways, but His ways always lead to the right conclusion.