A person may sometimes get swelling on his leg and may have limped a few times—but he is never called lame.
You are right.
Similarly, sometimes a person may slip into selfishness and use his free-will to his own harm or to the harm of others—but this does not make him a sinner because the ability to do the contrary (ability choose to commit virtuous act to any extent) too exists in him.
This ability of doing something contrary to God’s acceptable standard is called Sin (missing the mark). We are called captives to sin, not just because we are sinning, but because we have the tendency to sin. And anything, how matter small, that we do which falls short of the glory of God is called Sin and the person, a sinner.
If one’s occasional sinning does not make him a sinner, sin of another person (such as first human couple) can never make others sinners.
To put it this way, another person’s crime does not make me a criminal. But this is not the case with Sin. Crime is a legal concept applicable only to the perpetrator. However, Sin is not a legal term or a concept; it is an inclination or a condition. According to the law of heredity, a parent organism passes on its physical and personality traits to its progeny. Similarly, Sin got passed on to the offspring of Adam. It was not a simultaneous effect, but a progressive effect.
That means there cannot be something called original sin. If there is no original sin, there is no need for God to send one of His children to die for the sins of other children. Interestingly, Jesus himself testifies that God sent him from heaven not to die for any body’s sin. (Mathew 21:33-36)
Adam and Eve did sin and pass on its effect on their progeny- who did not sin or transgress (Romans 5:14). We are not participants of Adams sin, instead, we are the inheritors of Adams sin. We are not Sinners in the way that we deliberately sin. But we are all captives of Sin. Hence the need for ransom.
Even if he is murdered (which is a sin), how can that be a means for atonement of sins of others—sin atoning sin?
I use the term sacrifice, rather than murder. A soldier who dies due to a bullet shot from an enemy can be in a literal sense called as executed or murdered. However, contextually we call it as a sacrifice or martyrdom. Parents who allow their children to join the army very well know that their children face the risk of death in the battlefield. However, we do not call a slain soldiers parent as murderers, neither do we call the soldiers death a murder. We call it a sacrifice or martyrdom. Similarly, I don’t consider Jesus death as a murder. It was a sin for the one who killed Jesus, however in the grand scheme of things Jesus death was a sacrifice. The way a soldiers sacrifice impacts us, similarly is Jesus death (that’s the topic of Ransom). So it is Sacrifice atoning Sin, not Sin atoning Sin.
Besides, murder doesn’t really count if he gets to come back to life three days later.
That’s where the concept of Ransom (and not murder) comes in. It was not - a man killed and then brought back to life. It was - A spirit life from heaven takes a perfect human form, sacrifices it and returns back to its spirit form in heaven
