I disagree. Even if the innocent is willing, it is unjust to punish the innocent for the crimes of the guilty. That, in my opinion, is the significance of the verse in question. Let me ask you -- how do you reconcile Ezekiel 18:20 with your beliefs about the sacrificial death of Jesus?
But isn't that the essense of the sacrificial system which God commanded for the Israelites ? If death (whether of the guilty of a sacrifice) is not required, what is God doing with the Israelites in the Old Testament ?
Its not. This is particularly made clear in the later prophets. Just one of many examples:
For I desire steadfast love and not sacrifice,
the knowledge of God, rather than burnt offerings. (Hosea 6:6)
what is God doing with the Israelites in the Old Testament ?
Good question. What is the purpose of the sacrifice? Do we really think that God is somehow appeased for a sin by the killing of a lamb? In fact, we know that He is not:
The sacrifice of the wicked is an abomination to the LORD,
but the prayer of the upright is his delight. (Proverbs 15:8)
So we can see that it is not the sacrifice itself that God desires, but rather what it is supposed to represent. Sacrifice without repentance is meaningless, and in fact, an "abomination". However, sacrifice can be a symbol of true repentance.
The question is, what sort of sacrifice does God truly desire, and why would He have established something different? Maimonides, the great Jewish philosopher and theologian, considered this question. In viewing the history of sacrifice in the scripture, he came to the conclusion that God was weaning Israel away from animal sacrifice. The Law regarding sacrifice grew progressively more restrictive. First, they could be offered anywhere, then later only in Jerusalem at the temple. Maimonides believed that God accepted the sacrifices as a concession to the wishes of the Israelites to offer sacrifices to Him as neighboring tribes did to their gods. (Remember Jesus saying that Moses permitted divorce "for your hardness of heart"? This is similar). As time passed, God revealed to Israel what He really desired.
For thou hast no delight in sacrifice;
were I to give a burnt offering, thou wouldst not be pleased.
The sacrifice acceptable to God is a broken spirit;
a broken and contrite heart, O God, thou wilt not despise. (Psalm 51:16-17)
With what shall I come before the LORD,
and bow myself before God on high?
Shall I come before him with burnt offerings,
with calves a year old?
Will the LORD be pleased with thousands of rams,
with ten thousands of rivers of oil?
Shall I give my first-born for my transgression,
the fruit of my body for the sin of my soul?
He has showed you, O man, what is good;
and what does the LORD require of you
but to do justice, and to love kindness,
and to walk humbly with your God? (Micah 6:6-8)