Using "Acts of God" in legal term

I wonder why on a lot of legal term in English country using "Acts of God" as an events outside human control?

As an Indonesian, I think everything that happens in this world is an act of God. And it reminds me one of The Simpsons episode "Sky Police" which Chief Wiggum crash to a church and the insurance companies won't cover it because Reverend Lovejoy said it's an "acts of God."

Why not use the term "natural disaster"? In Indonesia, if you say it's a natural disaster, the company cannot be blamed for a mistake they've made, like "Lumpur Sidoarjo."

Solution 1:

"Act of God" is a legal definition:

An act of God is a legal term for events outside human control, such as sudden natural disasters, for which no one can be held responsible.

Probably its origin as a legal expression is because it is closely related to natural disaster, that is something that is beyond human control:

The phrase “act of God” is sometimes used to attribute an event to divine intervention. Often it is used in conjunction with a natural disaster or tragic event.

Wikipedia

According to online Etymology Dictionary :

" Act of God "uncontrollable natural force" recorded by 1726.

Solution 2:

Act of God is describing naturally occuring events over which we humans could not predict, or predict its severity. Eg, an IT company's building housing hundreds of servers used by the public gets struck by lightening and gets taken offline. The public users depending on the up keep of servers for their business my loose some income while they work to get the servers running again. But getting struck by lightening was an 'act of God'. Random event happening such as a lightening strike, which is not really a 'natural disaster' on a big scale, but locally to that one building whose servers went offline, would be Act of God. However if someone working at the company maliciously causes data loses then its different.

Also, you say "As Indonesian, I think everything happen in this world is acts of God" but it can't be everything, eg. it was you, who came online and wrote the question, it wasn't God doing it...Legally or Spiritually you have to take responsibility for your actions.