This sort of belief that a groovy God simply dispenses blessings to people who don't irritate him by trying to work for them clearly hampers Liz and the other children in three distinct, horrible ways. The first horrible way came into play when she gushed about how cool it is that someone's marriage fell apart so that she could have work close to home. Since she was fated to get that job, that marriage was fated to collapse so the person crying her eyes out should take comfort that her misery was preordained and also helped guide Liz's destiny. Similarly, there's no need to feel sorry for evil career women or fallen pop stars because they denied the self-evident truth about how their real fate is to scurry around and give the Patterson family free things so that they can feel good about themselves because an evil voice that loves chaos tells them that the Pattersons actually have to earn things like they were boring, ordinary people.
This leads us to the second horrible way that Elly's belief that the Fates run the Universe ruin her and the kids: it allows her and the others to once and for all dispense with the need to be grateful for what she has around her or thankful for the hard work of other people. Since things are supposed to happen the way they do, it makes no sense to reward people for the inevitable. It also allows her and those who model themselves on her to dispense with empathy for those who do things to disappoint or inconvenience them. Take, as by of example, Lizzie's losing her eyeglasses. We see a kid flaking out and losing something. Elly sees an avatar of chaos who, for evil reasons that evil people call having totally unfair free will, defies her fate to always make her mother's life a minimum cinch trying to make her buy eyeglasses in bulk to ruin her because the alternative is that being guided by fate and faith doesn't happen and one has to earn happy endings and make life meaningful. Sadly, existence precedes essence and we have to kick at the darkness until it bleeds daylight. Elly would rather not because it means that she's responsible for what's going on around her and doesn't feel like feeling guilty.
This leads us to the third horrible way believing in the miracle harms Elly and the others is that doing so means that they can dispense with being aware of their surroundings. An odd passage in the book "The Lives Behind The Lines" has Elly learn that dating means nothing more than tear-stained pillows after promised phone calls never came. What Elly is to this day not aware of is that said calls were made to not come by a fear-filled paterfamilias who, should his actions to 'defend' Elly from a 'threat' have come to light, would no more apologize for stopping something harmless merely because it threatened his fragile ego than Greg does for treating Lawrence as if he's radioactive. Simply put, believing in magic means having your head up your arse and loving it.