Psalms 30:6 - Albert Barnes' Notes on the Bible

And in my prosperity I said, I shall never be moved - I shall never be visited with calamity or trial. This refers to a past period of his life, when everything seemed to be prosperous, and when he had drawn around him so many comforts, and had apparently made them so secure, that it seemed as if they could never be taken from him, or as if he had nothing to fear. To what precise period of his life the psalmist refers, it is now impossible to ascertain. It is sufficient to say, that men are often substantially in that state of mind. They have such vigorous constitutions and such continued health; their plans are so uniformly crowned with success; everything which they touch so certainly turns to gold, and every enterprise so certainly succeeds; they have so many and such warmly attached friends; they have accumulated so much property, and it is so safely invested - that it seems as if they were never to know reverses, and they unconsciously suffer the illusion to pass over the mind that they are never to see changes, and that they have nothing to dread. They become self-confident. They forget their dependence on God. In their own minds they trace their success to their own efforts, tact and skill, rather than to God. They become worldly-minded, and it is necessary for God to teach them how easily he can sweep all this away - and thus to bring them back to a right view of the uncertainty of all earthly things. Health fails, or friends die, or property takes wings and flies away; and God accomplishes his purpose - a purpose invaluable to them - by showing them their dependence on Himself, and by teaching them that permanent and certain happiness and security are to be found in Him alone.