God had to punish them and as a consequence, death and suffering entered the world. This was the beginning of suffering. Sin is the cause of suffering. Not desire. Unfortunately the only way to pay off this debt - this bad karma - is to offer a perfect sacrifice in payment of this karmic debt. But because of sin, man is no longer perfect and so we are unable to pay this debt. No amount of meditation or good deeds will ever clear our karmic debt or save us from suffering. God is perfect and so His standards are perfect. We would have to live absolutely perfect lives without any bad karma or any sin. And this is a standard nobody can live up to. In fact as a consequence of any sin - any bad karma - God has to punish us eternally.