Something which is glued to another can only be taken off by tearing. So, it is a sign your heart is glued to the world that when God would take you away from something in the world, your heart tears. If God, by suffering, should come to take anything in the world away from you and you can part from it with ease, without tearing, it is a sign then that your heart is not glued to the world. (Taken from The Rare Jewel of Christian Contentment, p. 59).
Christ is the One to whom our hearts should be glued. If we glue them to anything else, we are just asking to be ripped to pieces.