In dying, the incarnate God paid the sin debt of every human being.  There is no confusion at that level.

The confusion sets in from a misunderstanding of what the debt of sin actually is, and what it meant for Christ to pay it.  The most traditional Christian interpretation has it that the debt is the punishment required by God’s justice as a result of the sin, and that Christ’s payment consists in having vicariously accepted that punishment in the sinner’s stead.  But this is mistaken, and the reality is more complicated.

God is Love. Sin is acting contrary to the will of God, and that means acting contrary to the will of Love.  To sin against someone is to act towards that person in a way other than as Love would act.  The one sinned against is thereby deprived of what Love would have provided him.  And Love itself – that is to say, God – is diminished by the amount of the Love I have denied the other.  That is the twofold result of sin: What you do to others, you do to Me.

In that way, two spiritual debts are created by every sinful act. There is a debt incurred towards the one sinned against, and a debt incurred towards God.

In both cases, the so-called sin debt is best understood as a Love debt.

The death of Christ, that is, the death of the incarnate Son, was perfect Love exhausting Itself to pay your timeless Love debt to God.  If Christ is in you, then you are debt-free to God.  That is the Christian promise.

The love debts others owe me can be paid by my self-sacrificial forgiveness.  If I am in Christ, my payment also repays God, and thereby relieves in some part Christ’s timeless burden. That is the Christian privilege.