I have no knowledge of the people involved, but Joe Carter has an excellent post on the nature of sin:
What is truly amazing is how patient and forbearing God has been throughout history in light of our continued betrayal. Look, for example, at the examples in the Old Testament. Those who refuse to recognize God’s holiness often complain that Jehovah is cruel and vindictive. In truth, God’s dealings with humanity in the OT are an example of a God who is maddeningly patient and merciful.
The punishment for sin is death—complete physical and spiritual death. Yet over and over God foregos enacting his righteous judgment (justice) and treats mankind with mercy (nonjustice). It is a sign of our skewed perspective that we are shocked when we read about God slaying the wicked. What should surprise us is that God isn’t infinitely just, continually slaying all wicked sinners.
Which is why I'm glad God answers the prayer, "God, be merciful to me, a sinner!" Otherwise, all would be lost for everyone.
Joe quotes RC Sproul who compares sin, even minor sin, to treason against God. I don't have the time to look it up, but CS Lewis made a similar comparison. He explained that sin is an act of civil war against the Almighty. That is why you can't expect God to take you back without repentance. Repentance is the act of laying down your arms and surrendering to God. Asking God to take you back without repenting is, essentially, asking him to take you back without, you know, actually going back. (While taking pot shots at him to boot.)