We as humans are capable of sinning, yet for the majority we don't. Of course we do still commit sins. Yet God isn't a human. God isn't a person at all.
If God is all powerful, or at least powerful enough to create the world. Then God would be able to not sin.
That I don't believe.
If something was to be an ultimate truth it would be constant within all religions. The belief in one God is a constant, so any other religious truths must also be constant. If they aren't then they aren't ultimate truths. The founding principles of all religions are the same, they are the ultimate truths, and that includes sin, true sin as opposed to the propaganda sins that have been spread by every religion in existence once the prophets died.
In the Pagan/Wiccan faiths, we have a sabbat called Beltane which is the sabbat of Love and Fertility, and involves handfastings, sexual activity with your partner, and the energies in Love.
Some would call such a thing a lustful and decadent practice in sexual deviancy, and thus a sin in the eyes of Christianity.
While the Pagan/Wiccan goddess wouldn't have it any other way.
A lot rides on perception and the differences thereof. One god or goddess' sin is another's normal part of their faith.
I personally think the Goddess I believe in is fully capable of sin, but would not allow herself to be tempted and corrupted by it. She supports love and healthy sexuality, but not promiscuity and unhealthy sexual deviancy or anything wrong like pederasty or non-consensual encounters. She has a love for all who follow her.
Also, Wiccan magicks are very complex and balanced. Using them for personal material gain is a no-no, but using a spell to protect ones you love or to expose or harm a wrongdoer (Such as the "Expose Wrongdoer" or "Rule of Three" spells specifically) is perfectly fine. The magicks also work stronger if you channel their effects to another person rather than yourself. You and your partner could feasibly each cast a spell to protect their partner, and their love would strengthen the spell exponentially.
Regardless of all this, The Goddess frowns upon harming the innocent or material gain from the spells, and will harm the spell caster him/herself in the process by the energies backfiring.
For example, you hate someone who's done nothing wrong to you. You cast a spell on them to make their hair fall out. They've not wronged you or another you know, and so your spell would come back and its effects would befall yourself as punishment.
The Goddess has her rules just like any other god or goddess, and she punishes you for breaking them in a more worldly sense. Similar to Christianity I guess, but the effects of breaking the Wiccan rules can harm you in life more often than in the afterlife.
1st- The paradigm is one used the the basic beliefs of all three Abrahamic religions. If God created Adam and Adam begot the human race, than humans are God's children.
2nd- A perfect God cannot create imperfection. It doesn't matter who he would create it for. Which means sin is part of perfection, which means if God is perfect then God can sin.
I don't think God can sin. Though He created sin itself as an imperfection, this doesn't mean that He does sin. Even humans themselves can not sin if they try to live their lives perfectly clean(if they can do it.). Jesus is also the one man who did not commit any sin during his life.
But some says that God is not real. They say that people created a "God" so that no other human in the world could make themselves very powerful or "Godlike". That means, sins are not entirely applicable in the lives of man. At least, that's what atheists say.
And many times I get convinced over that statement. Humanity is no-where to be found, and when I see a few good people, I am against the statement.