There are a lot of words meaning "disobedience to authority" but I'm wondering if there's any word for "disobedience to God". I mean a technical term or something.
1a: an offense against religious or moral law
1b: an action that is or is felt to be highly reprehensible
2a: transgression of the law of God
to commit a sin
It is not used to exclusively describe disobedience to God, but has those connotations:
It's a sin to waste food.
Bless me, Father, for I have sinned.
Ordinarily the sinful cleric prayed and fasted at his own discretion, and nothing is said of his confessing his sins.
Speaking as a AmE I tend to connect this to the Christian god, but that may be due to overexposure to Christianity, rather than actual usage rules.
If you want to describe "disobedience" to the point of "rejecting God's authority", you should definitely consider "apostasy".
apos·ta·sy | \ ə-ˈpäs-tə-sē \
Definition of apostasy
1 : an act of refusing to continue to follow, obey, or recognize a religious faith
2 : abandonment of a previous loyalty : DEFECTION
If you disobey God, you are being sacrilegious:
: committing or characterized by sacrilege : having or showing a lack of proper respect for a sacred person, place, or object
// sacrilegious acts
// It is difficult for religiously committed persons to acknowledge that their sacred texts are prone to sacrilegious uses.
— Mary C. Boys
Note that it goes on to mention uses of the word in non-religious contexts (but no doubt coming from that use metaphorically):
—often used in an exaggerated way in contexts unrelated to religion
// It would be sacrilegious to cut down such beautiful trees.
// Chilling your red wines may seem sacrilegious to some, and downright odd to others.
— Tess Rose Lampert
However, context would make its context clear.
Also, for sacrilege (if you prefer a noun rather than an adjective):
: gross irreverence toward a hallowed person, place, or thing
How about heresy?
According to Merriam-Webster:
1 a : adherence to a religious opinion contrary to church dogma (see dogma sense 2)
They were accused of heresy.
b : denial of a revealed truth by a baptized member of the Roman Catholic Church
c : an opinion or doctrine contrary to church dogma
I like the Cambridge definition a bit better:
a belief opposed to the official belief of a church and that is considered wrong, or the condition of having such beliefs
To be fair, I should say that both dictionaries have definitions with non-religious contexts, as well. According to etymology online, its first popular usage was in the New Testament, and was not used as a secular term until the 14th Century, so it has a religious pedigree.
It is, obviously, a Christian-centric term, and it assumes that having an opinion contrary to Church dogma is equivalent to disobedience to God, but this is the best word I can suggest.
- impious utterance or action concerning God or sacred things.
- an act of cursing or reviling God.
(Random House via TFD).
Although this is changing over time to be more generalised to "sacred things" rather than God.
How about defy or defiance?
Denounce is another that comes to mind, but this implies rejection (apostasy) more than it does disobedience - but that can differ depending on one's relationship with scripture - to some 'followers' these terms may effectively mean the same thing.
One of the suggestions made above, heresy - from the Greek for 'choice' - is particularly apt here. Whereby the heretic exercises their free-will by deliberately choosing to defy god.
Apostasy perhaps? According to Merriam-Webster:
an act of refusing to continue to follow, obey, or recognize a religious faith