Parenting is such a beautiful thing, but difficult in the same time. Who says raising a child is a simple work? It is not. To be a parent means so many things and is such a complex task. When we desire a child from the bottom of our hearts, we do not trully realize that this is more than a wish, as a child is a human being who has needs, who has to be understood according to his age, to be loved, and, most of all, educated. Yes, raising a child doesn't mean only feeding, loving or simply having him around (although there are parents who consider this enough); it's more than that.
Being a parent means to make sacrifices, to make efforts, to reduce your own time and give all the attention to your child. But what if in his efforts to educate his child, a parent slaps his child accidentally, even if he is a loving parent, and he adores his baby? Should we judge it or not? I often hear parents who say: "How could I beat my own child? Is it so difficult to educate him by words?" This is a reasoning question, I agree with that, but I also believe that there are loving parents who suffer and feel guilty enough for an accidental behavior like that, and who also agree that this is a mistake, but, in spite of that they sometimes do it. And I'm sure that all the loving parents agree that slapping a child has no result, but finding solutions by words and arguments is the best way to educate a child. 
On the other hand, never say never. Only God can judge. There are so many parents who say in public that they'd never do this, but when they are in the intimacy of their place, they behave differently with their children. I've learned not to judge the parents and their education methods, as long as they are loving parents, and they regret a slap, and feel guilty for their actions. Besides, the one without a sin, should be the first to fling a stone, as Jesus said. I used to judge parents from many points of view, before I had my own child. I saw things differently, and every misbehavior seemed to me strange and awful. But now, when I have my own experience as a parent, I understood that children are complex human beings, that they are not robots, and have their particular personalities. And especially when a child has a strong personality, it's harder to educate him, and our efforts are doubled, patience, too, and frustration is bigger.
A parent often feels frustrated when dealing with a toddler of 2, 3 or 4 years old. And, sometimes, when his education resources are exhausted, frustration determines him to inoffensively beat the child. Is it wrong? Of course it is! But this is the reality, and we should not condemn parents who do this, as long as they are loving parents. Instead, is more judgeful a parent who doesn't show love to his child, who doesn't pay him attention, who doesn't feel any guilt when spanking his child, or a parent who regularly apply this kind of education. As long as parents realize which kind of education is better, by words and explanations or by beating, than this is ok. But usually many parents choose the simplest way, education by beating, without even making efforts to explain their child what is good or wrong. We should think if we want our children to become good persons, with no frustrations and educated people. Children copy our behavior, and when they are little, they draw the conclusion that all what we do is good. That is why we should avoid wrong behavior, bad reactions, and be gentle, patient, positive...
We should know that in 37 countries around the world (Sweden, Finland, Norway, Austria, Cyprus, Denmark, Latvia, Croatia, Bulgaria, Israel, Germany, Turkmenistan, Iceland, Ukraine, Romania, Hungary, Greece, Netherlands, New Zealand, Portugal, Uruguay, Venezuela, Spain, Togo, Costa Rica, Republic of Moldova, Luxembourg, Liechtenstein, Poland, Tunisia, Kenya, Republic of Congo, Albania, South Sudan, Macedonia, Honduras, and Malta), it is illegal for a parent, teacher, or anyone else to spank a child, and 113 countries prohibit corporal punishment in schools. Yet in all of North America, physical punishment by a parent, as long as it is not severe, is still seen by many as necessary discipline, and condoned, or sadly, even encouraged.
We should think about our mistakes, and choose what kind of parent we want to be: the inteligent parent, who chooses the hardest way of education (the loving parent who has patience, limits, explanations and arguments), or the good parent, who chooses the simplest way of education (the loving parent who allows his child to do whatever he wants, who spoils his child, who pleases his child just to comfort him).