Final answer:
The relationship between sin and grace in the atonement can be described as sacrifice or reparation. Jesus' sacrifice on the cross was a necessary payment for the debt of sin, leading to forgiveness and redemption through grace.
Step-by-step explanation:
In the context of the question, the relationship between sin and grace in the atonement can be described as sacrifice or reparation. Sacrifice refers to the act of Jesus willingly offering himself as a sacrifice for the sins of humanity. This sacrifice is seen as a way to reconcile humans with God and restore the broken relationship caused by sin. Reparation, on the other hand, emphasizes the idea that Jesus' sacrifice on the cross was a necessary payment for the debt of sin. It was through his death and resurrection that grace is made available to believers, offering forgiveness and redemption.