(Luke 15: 11-32)
Those who deny, ignore, or hate God are still happy to make use of the good things he has given them. In fact, we all fall into this error because we have all made use of or enjoyed created things without putting them in their proper context as things created by God. And this is what we call sin.
Sin is a sort of death. Repentance is a participation in the Resurrection.
We tend to think of repentance as a returning to God, but it is more properly a 'coming to our senses,' a 'coming back to ourselves' that puts us back in touch with our most real and best selves, the selves that recognize the God who is always arriving in order to meet us.
The confession of the sins that have separated us from God's embrace is only of interest to him insofar as it is the means by which we accept that embrace anew.
It is just as easy for 'religious' people to lose their sense of God's goodness as it is for 'sinners.' Perhaps it's even easier in some cases. This is because righteous people easily forget that they are just as much sinners as are the 'sinners,' because all sin is overwhelmingly offensive before the infinite loving-kindness of God. It is also because righteous people sometimes don't recognize--and confess--how much of their religion is of the flesh. Helpfully, however, this latter condition is revealed by the emotion of resentment that arises at the gifts God gives to another, and in this it can be recognized and perhaps mortified.