Saying things like that may not seem so cruel when written out, but imagine it happening to you as a child.
You're waiting in front of your mom's house one cold November Friday afternoon. You just got out of school, you dumped your school bag by your computer, and you opted to wait outside for your dad to pick you up to bring you to his house which is about an hour north of your mom's (you choose to wait, so you didn't feel rushed in getting out the door and promptly spending the next few hours worrying over whether you locked the front door or not. Anxiety sucks like that sometimes.)
A car pulls onto your street and a shiver rolls down your spine. Not him. You didn't want him to pick you up. You quickly look at your phone, praying that dad didn't send you a text saying that your step brother was going to pick you up, that he just took the wrong turn getting to his work which happens to be right on the other side of town. Your stomach sinks as you see the (1 new message - Dad) appear on your phone's front screen. As your brother pulls into the driveway, you shove the despair into the back of your mind and put on a happy face. If you keep him distracted well enough, maybe he'll choose not to focus on you.
Your flimsy hope shatters twenty minutes into the drive just as he pulls off the highway. Some Christian rap band is playing through the stereo, a cross hangs from the re-view mirror, and you run out of safe topics to discuss with him. Still in the back of your mind, you're kicking yourself for not doing well enough. You can just feel the mood in the car change as he gets ready to open his mouth.
The following forty minutes make you wish you can just roll out the car and run back home, get back to the safety of your mom and your cat. He starts off innocuously, mentioning the band and its (mediocre) rhymes about Jesus.
He then shifts his focus on you, you poor little sinner child, only fifteen years old and already breaking so many commandments. He begins critiquing you, bringing up your boyfriend of five months, bringing up your history of paganism, your depression, your attempt at vegetarianism. Anything he can get his pure and born-again hands on. He conjures up the most incredible descriptions of your eternal suffering in Hell, abandoned by God, unloved and forgotten by everyone including yourself. He insults your mother, who loves you no matter what you do. Then he begins grilling you on what you know of the Bible, verbally tearing you apart every time you make even the slightest error in his mind.
By the time you reach the house, you're trembling with self loathing, anger, sorrow. You quickly dart up the hill to the front door as he heads into his apartment in the basement, promising that he'll stop by to say hi sometime later.
Years pass, he has since realized his abusive tactics and apologized for them, which gives you some form of relief, but you choose not to forgive him. You can no longer listen to Christian music, listen to any religious sermon, talk about Christianity in any fashion without having to completely mentally shut down to prevent yourself from blowing up in a fit of rage. Or throwing up. Or both. All of three have happened before. You speak with a therapist on a weekly basis now, discussing the forms of abuse that have happened to you, about your relationship with any devoutly religious person, about the time you were caught trying to kill yourself directly because of your step brother's abuse. But the pain won't go away. That entire year was tainted by the constant presence of your step brother in your life. And the abuse haunts you to this day. And every time you try to tell someone, they always brush it off as just being shitty and not actually criminal, despite the psychologically scarring events that have happened to you leaving you constantly wondering what did you do to deserve this punishment.