"If the first and lowest operation of pain shatters the illusion that all is well, the second shatters the illusion that what we have, whether good or bad in itself, is our own and enough for us. Everyone has noticed how hard it is to turn our thoughts to God when everything is going well with us. We 'have all we want' is a terrible saying when 'all' does not include God. We find God an interruption. As St. Augustine says somewhere, 'God wants to give us something, but cannot, because our hands are full-- there's nowhere for Him to put it.' Or as a friend of mine said, 'We regard God as an airman regards his parachute; it's there for emergencies but he hope he'll never have to use it.' Now God, who has made us, knows what we are and that our happiness lies in Him. Yet we will not seek it in him as long as he leaves us any other resort where it can even plausibly be looked for. While what we call 'our own life' remains agreeable we will not surrender it to Him. What then can God do in our interests but make 'our own life' less agreeable to us, and take away the plausible source of false happiness."
--The Problem of Pain