When love dries in a marriage, the children become mortar for the bricks. When the children leave, the bricks just sit atop each other. When the children die, the bricks tumble.
The quote from Mitch Albom's "First Phone Call from Heaven" illustrates the idea that children often serve as a binding force in a marriage where love has diminished. In such situations, parents may cling to their children as a way to maintain their relationship, using them as a support system that holds the family structure together. Without the presence of children, the underlying issues in the marriage become more apparent, causing tension and instability.