In this Psalm, the psalmist cries out to God to search him, but since he starts with an acknowledgement that God has searched him and does know him the invitation is really to make him aware of what God is aware of but he is not. It is a prayer expressing the desire that all of his actions, desires, thoughts, his will would be brought into alignment with God’s. It is an invitation to God to do what is necessary to make that happen. It is a dangerous prayer for us to pray because it could change our whole world, but it is also dangerous because if we were to pray it honestly as a community God could use it to change the whole world.