Have you ever known people who were drawn to every new fad or idea? Such people are unstable and therefore unreliable. The secret to stability is to trust in God, because he never changes. He cannot be shaken by the changes in our world, and he endures forever. The fads and ideas of our world, and our world itself, will not.
Psalms 125:3
Although the writer said, "The wicked will not rule the land of the godly," often Israel had to put up with evil rulers. The writer was expressing what will ultimately happen when God executes his final judgment. Human sinfulness often ruins God's ideal on earth, but that doesn't mean God has lost control. Evil prevails only as long as God allows.