In the article on The Atonement, he defended the Penal Substitutionary Theory (PST) against the Moral Influence Theory which was then, and is now the main theory advocated by religious liberals. He writes:
First, it is said that the doctrine of substitution supposes that which is impossible. Guilt cannot be transferred from one person to another. Punishment and penalty cannot be transferred from a guilty person to an innocent one. An innocent person may be charged with sin, but if so he will be innocent still, and not guilty.Johnson makes two arguments in the above quote. First, he says that the objection raised against the PST is primarily "over the definition of words." He believes that it is really just a matter of semantics. I disagree. The issue is over how an innocent can justly pay the penalty for what the guilty deserves. Whatever terms one uses to describe this scenario, the problem remains.
An innocent person may suffer, but if so his suffering will not be punishment or penalty. Such is the objection: the Christian world, in believing that a substitutionary atonement has been made by Christ, believes a thing which is contrary to the necessary laws of thought.
The reader will observe that this objection has to do wholly with the definitions of the words guilt and punishment and penalty [emphasis his]. It is perhaps worthy the serious attention of the theologian who wishes to keep his terms free from offence; but it has no force beyond the sphere of verbal criticism. It is true that guilt, in the sense of personal blameworthiness, cannot be transferred from the wrong-doer to the well-doer. It is true that punishment, in the sense of penalty inflicted for personal blameworthiness, cannot be transferred from the wrongdoer to the well-doer. This is no discovery, and it is maintained as earnestly by those who believe in a substitutionary atonement as those who deny it.
Let us use other words, if these are not clear, but let us hold fast the truth which they were once used to express. The world is so constituted that it bears the idea of substitution engraved upon its very heart. No man or woman or child escapes from suffering inflicted for the faults of others. In thousands of instances these substitutionary sufferings are assumed voluntarily, and are useful. Husbands suffer in order to deliver wives from sufferings richly deserved. Wives suffer in order to deliver husbands from sufferings richly deserved. Children suffer in order to deliver parents from sufferings richly deserved. Parents suffer in order to deliver children from sufferings richly deserved. Pastors often shield guilty churches in this way, and sometimes at the cost of life. Statesmen often shield guilty nations in this way, and sometimes at the cost of life. If now we shall teach that Christ suffered in order to deliver us from sufferings which we richly deserved, we shall avoid a strife about words, and shall maintain that, coming into the world as a member of our race, He suffered to the utmost, as many other heroic souls have suffered in a lesser degree, by subjecting Himself to be a common rule of vicarious suffering, instituted by God in the formation of human society bound together by ties of sympathy and love, and existing in daily operation from the dawn of history till this present time ("The Atonement," in Theology at the Dawn of the Twentieth Century, ed. John Vyrnwy Morgan, pp. 262-64).
Second, he says that by restating the doctrine to the effect "that Christ suffered in order to deliver us from sufferings which we richly deserved," the problem is resolved because we know from experience that people suffer in place of others all the time. Yes, it is true that innocent people often suffer in place of those who really deserve the suffering but does that make it "just?" If a parent chooses to suffer the consequences of some act committed by his or her child and thereby shield the child from the consequences, is that the same thing as "penal substitution"? No, I maintain that it is not. A parent may be noble and virtuous in doing such for his child but the question still remains: "Would the inflictor of the suffering (i.e., a personal agent such as a Judge) consider it justifiable to punish the parent instead of the child?" I don't think so. It may be that due to the way natural consequences of acts turn out, others besides the guilty person may suffer but that is not the same as singling out an innocent person and having him intentionally bear the punishment due the guilty party which is what the PST teaches.
The second argument by means of which the advocates of "the moral influence theory" seek to refute the doctrine of a substitutionary atonement is equally unfortunate with the first, in that, like the first, it criticizes words, rather than the thoughts which they are employed to express. The doctrine of a substitutionary atonement, it is said, is immoral. Let us inquire what this immoral doctrine is. The doctrine, it is answered, is that our guilt was transferred to Christ and that He was punished for our sins. Here again let us "strive not about words." Let us admit that the theologian might well express himself in other terms, which would create no prejudice against his meaning. But, if he amends his statement, let him retain every part of his meaning. Let him say that Christ suffered in order that guilty man might escape from sufferings richly deserved. Is this teaching immoral? Then the constitution of the human race, ordained by God, is immoral, for, since its ties are those of sympathy and love, human beings are constantly suffering that others may escape sufferings richly deserved. Then sympathy is immoral, for this is what it does. Then love is immoral, for this is what it does. Then the best persons are the most immoral, for they do this oftener than others (pp. 264-65).
Johnson argues that "penal substitution" is not immoral because the one who volunteers to take the place of the guilty does so out of sympathy and love. He says that human beings are constantly suffering that others may escape sufferings richly deserved. This is true but it is a red-herring; it has nothing to do with the administration of justice. Again, no one questions the virtue of one who would volunteer to suffer in the place of another, but that is not the problem. The issue is: How could one who administrates justice allow it to happen (since it is not just) and how could the suffering of the innocent suffice to pay the penalty owed by the guilty? These problems are not addressed by Johnson.