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Your answer is good, but the question is wrong!
When we begin to see sin as God sees it, the question should be why doesn't God punish us all as he did Achan?
Thank God, the answer is His matchless, awesome Grace! Because of His grace, His mercy reaches out and we are none of us punished as we deserve. What a cross! What a Saviour!
Agree Terry. We all have a life we do not deserve. His Love, beyond our comprehension, gives us much more than we could ever dream of earning. We are helpless without Him. He is All in all!