Instead of overreacting, I believe we should maintain a distinction between what is acceptable physical discipline and what constitutes actual abuse. This allows us to condemn the latter without outlawing the former. Throughout this article I will refrain from using the word “punishment” when describing parental responses to disobedience. Punishment, strictly speaking, is primarily concerned with subjecting guilty persons to penalties without regard for either their moral improvement or personal well being. An extreme example of punitive action is the death penalty, which punishes without any interest in improving those who receive it. Worse still is the idea of parents inflicting pain upon children merely to “get back” at them or vent anger.
In contrast to this, chastening entails discipline that is concerned for the person being disciplined. The bible teaches parents to model their discipline on the way believers are chastened by their Father in heaven. Proper chastening is then motivated by love, not wrath. Its purpose is to bring about the long-term moral improvement and personal well being of those who receive it.
“Whoever spares the rod hates his son, but he who loves him is diligent to discipline him.” [Prov. 13:24]
“The rod and reproof give wisdom, but a child left to himself brings shame to his mother.” [Prov. 29:15]
LIMITS OF CORPORAL DISCIPLINE
Parents are to administer physical force only during the brief period of development when children are most likely to understand and respond to the swift discomfort and shame it causes. As children mature the rod is exchanged for reason and, in extreme cases, civil authorities. [Exo. 21:15] Scripture limits physical discipline to a child’s backside. More than once the Apostle Paul emphasizes that fathers should not exasperate their children. [Col. 3:21, Eph. 6:4] This implies limits of force, both mentally and physically. No physical response should bring lasting physical damage.
“For the Lord disciplines the one he loves, and chastises every son whom he receives. It is for discipline that you have to endure. God is treating you as sons. For what son is there whom his father does not discipline?” [Heb. 12:6-7]
Furthermore, discipline should be administered in proportion to wrongs committed, and with regard to a child’s age and constitution. Pain should never be inflicted out of vengeance or wrath, nor as an end in itself. The hand which holds the rod must be energized by love and should as quickly extend itself to comfort and assure children once they have been disciplined.
“Chasten your son while there is hope, and do not set your heart on his destruction.” [Prov 19:18]
Interestingly, the bible consistently advocates using a rod (literally, “that which branches off”, likely a switch) rather than the hand. Perhaps this is so children do not associate their parents’ hands with anything other than comfort and help. “Children should not be afraid that you are going to hit them when you reach your hand out to them. Don’t strike them with your hand; use your hands for giving them hugs!”  The very sight of a switch, preferably the same one, may induce a change of heart.
“Folly is bound up in the heart of a child, but the rod of discipline drives it far from him.” [Prov. 22:15]
REFLECTING ON MY OWN CHILDHOOD
To share an anecdote, in the rare instances of my childhood that my father believed spanking was warranted, he used to say, “Go into your room and consider how many times I’ve asked you to behave this or that way. When you realize that you’ve done wrong, come to my room.” At some point I would return and he would ask me to explain my faults. Then he would point out the escalations of warning and lesser penalties I received. Finally he would say,
“You are here because you have not believed bad actions result in bad consequences. You aren’t learning the lesson that obedience is best. As much as it hurts me to spank you, I know it will make you believe and recall the lesson: there are consequences in life for doing wrong, sometimes very painful ones. Do you understand?” Then my tail end would ignite memorably.
Of course I didn’t like being spanked, but my father’s reasonable way of handling these moments always convinced me he was right and concerned for my welfare. Afterwards he would hug me and say, “You’re a good boy. You just got a little off. I believe you’ll do better now. I love you and I’m not mad at you.” I hated the pain, but even then I loved him for it.
As a final note, if physical chastening by parents is ever criminalized, I believe Christians should obey God’s word even to the point of civil disobedience. Properly disciplining children is a moral imperative.
“Do not withhold discipline from a child; if you strike him with a rod, he will not die. If you strike him with the rod, you will save his soul from Sheol.” [Prov 23:13-14]