Robert Roberts in 1869 stated very plainly there was no miraculous change in Adam post the fall. Of course he changed his mind later but never really addressed his exposition of 1 Cor 15.
“But there is a misapprehension lurking under the proposition which we are combating. Our friend imagines there was a change in the nature of Adam when he became disobedient. There is no evidence of this whatever, and the presumption and evidence are entirely the contrary way. There was a change in Adam’s relation to his maker, but not in the nature of his organization. What are the facts? He was formed from the dust a “living soul,” or natural body. His mental constitution gave him moral relation to God. He was given a law to observe: the law he disobeyed, and sentence was passed that he (the disobedient living soul) should return to mother earth.
What was the difference between his position before disobedience and his position after? Simply this; that in the one case he was a living soul or natural body in probation for immortality; and in the other, he was a living soul or natural body under sentence of death. He was a living soul or natural body in both cases. The phrase “sin in the flesh” is metonymical. It is not expressive of a literal element or principle pervading the physical organization. Literally, sin is disobedience, or the act of rebellion.
The impulses that lead to this, reside in the flesh, and therefore come to be called by the name of the act to which they give birth. In determining first principles, we must be accurate in our conceptions. The impulses that lead to sin existed in Adam before disobedience, as much as they did afterwards; else disobedience would not have occurred. These impulses are in their own place legitimate enough. We can judge of this matter by experience, because the human nature under discussion is the human nature we have upon ourselves and see in operation around us. There is no such thing as essential evil or sin. Evil and sin are relative terms. There is no propensity but subserves a good purpose in its own place. Sin is forbidden use; evil, interference with desired conditions as a punishment of sin, sometimes flowing out of sin itself. The difficulty is to keep the impulses in the legitimate channel. This difficulty is insuperable so far as perfect righteousness is concerned. A child comes into the world with impulses, but no knowledge or experience to guide the action of them. The result is that “folly is bound up in the heart of a child,” which the judicious administration of the rod will help to take out of him—(Prov. 22:15). For the same reason, “there liveth not a man that (at some time of his life or other) sinneth not.”
The reason is to some extent applicable to Adam. He was in a state of innocency, or non-experience. Obedience seemed the natural thing till there was temptation. When good results were presented to the mind as the effect of disobedience, his want of experience left his mind a prey to the impulses excited by the prospect. Had he known experimentally that the path of disobedience was a path of thorns and death, he might have resisted the temptation.”
Brother Roberts. ‘The relation of Jesus to the Law of Sin and Death’, The Christadelphian Volume 6 page 85 (1869)
After this article he had to explain himself to readers, so to clarify made similar comments a few months later:
“My explanation is, first, as to ‘ran in the blood,’ ‘made sin,’ &c. Adam, before transgression, though a living soul (or natural body—1 Cor. 15:44–5), was not necessarily destined to die, as obedience would have ended in life immortal. After transgression, his relation to destiny was changed. Death (by sentence,) was constituted the inevitable upshot of his career. He was, therefore, in a new condition as regarded the future, though not in a new condition as regarded the actual state of his nature. In actual nature, he was a corruptible groundling before sentence, and a corruptible groundling after sentence; but there was this difference: before sentence, ultimate immortality was possible; after sentence, death was a certainty. This change in the destiny lying before him, was the result of sin. That is, his disobedience evoked from God a decree of ultimate dissolution. This was the sentence of death, which, though effecting no change as regarded his constitution at the moment it was pronounced, determined a great physical fact concerning his future experience, viz., that immortality, by change to spirit nature, was impossible, and decay and decease inevitable. The sentence of death, therefore, appertained to his physical nature, and was necessarily transmitted in his blood, to every being resulting from the propagation of his own species. This explains the first class of terms which seem to you to affirm sin to be a physical principle. The second class of expressions are, therefore, in harmony with the ideas embodied in the first; e.g., ‘there was a change in Adam’s relation to his maker (that is, in the purpose of God concerning the future of Adam’s experience: immortality being made impossible, and death inevitable); but not in the nature of his organization.’ Again, ‘it (sin in the flesh,) is not expressive of a literal element or principle pervading the physical organization,’ but of the impulses which lead to sin, and sin (in the results it evokes from the mind of God,) re-acts upon the flesh in bringing upon it a condition in which it is mortal, and physically impure.”
Roberts. “Notes on the Mystery of Godliness” Volume 6 page 242-243 1869