Can you explain the difference between “original sin” and just “ordinary” sin? If original sin is present at birth (conception) is that a rebellious act on the part of a baby, or just the consequence of Adam's sin that I must pay for? I understand rebellious sin in adulthood.
Original sin is a theological term that refers to the change in human nature that happened as Adam committed sin for the first time. His action changed his spiritual nature, and that new nature is inherited by all human beings. The change caused the spirit in humanity to enter a state of slavery to sin and broke fellowship with God. Every human being that came from Adam has shared in that fallen nature.
So we do not pay for Adam’s sin, because we have plenty of our own. Rather, we inherit Adam’s fallen sinful nature, and that nature leads us to sin from our very first breath. Pastor Armstrong calls this fallen nature a birth defect, and its effect is often summed up with the saying, “We are not sinners because we sin…we sin because we were born sinners.” Also, Jesus was born of a virgin without an earthly father so that He would not inherit that sin nature from Adam, and therefore He restarts the human race in His own likeness, hence His title as the “Second Adam”.
There is much more to say concerning this concept, so we HIGHLY recommend you listen to our Romans Bible study to go deeper into this concept and many others associated with our salvation. This is core, foundational Christian theology every believer should understand.