Probably the worst thing that a parent can do to a child is convince him that he is bad. It has worse effects than sexual abuse. It leads to self-hatred and a self-defeating, self-sabotaging behavior. The child becomes his own worst enemy. And it is extremely irresponsible to do that to a child.
My ex-wife’s mother was claiming that she was a bad seed. She however is a much better person than her mother. She has on many occasions gone far out of her way to help people from whom she had nothing to expect in return. Whereas her mother lives a selfish existence where she is not helping anyone.
If you think that your child is bad, it is your responsibility to influence the child to be better. But most people who claim such things have no such a thing in mind. They want to wield authority over the child without doing their part of loving the child. The harm that they do is real and lasting. And it makes them worse people for doing it.
I have always loved my daughter, and I have always ensured that she is treated well. I can say with full certainty that there is a better way. If you don’t love your child, give your child up for adoption. And if you choose to remain a parent, then be one responsibly.
Convincing your child that he is bad is completely irresponsible behavior. You make someone into his own worst enemy. This does not benefit you, and this does not benefit the family. It benefits your and your family’s enemies. And a responsible parent would steer away from that course of action however badly he thinks of his child.