What is meant by 'acts of mischief on earth'
30-11-2016 | IslamWeb
Question:
Assalaamu alaykum. Thank you very much for your last answer on my question. As an advanced student of Islam, I have often been asked what is meant by “spreading mischief on earth”. As Ibn Kathir puts it:
"(And when it is said to them: Do not make mischief on the earth) means, Do not commit acts of disobedience on the earth. Their mischief is disobeying Allah, because whoever disobeys Allah on the earth, or commands that Allah be disobeyed, he has committed mischief on the earth." http://www.qtafsir.com/index.php?option=com_content&task=view&id=436&Itemid=
I have a small collection of things that might be considered as “spreading mischief on earth,” such as disobeying Allaah (whether by Muslims or by disbelievers), which would mean disobeying the Sharia or spreading a religion than Islam, but I would like to ask you for an exhaustive answer that would involve all the acts/deeds that might be considered spreading mischief on earth so that I could forward them to my students. Thank You very much, and may Allaah reward you.
Answer:
All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad 
is His slave and Messenger.
Mischief on earth is done by committing Shirk (polytheism) and all sins. Tafseer At-Tabari reads, "The saying of Allah (which means): {And make not mischief upon the earth after its reformation. And invoke Him in fear and aspiration. Indeed, the mercy of Allah is near to the doers of good.} [Quran 7:56]; what Allah means by {And make not mischief upon the earth after its reformation.} is to not associate with Allah partners on the earth and to not disobey Him in it. This is mischief in it."
Tafseer As-Sa'di reads:
{And make not mischief upon the earth} by committing sins; {after its reformation}, i.e. with acts of obedience, because sins corrupt morals, deeds and livelihood, as Allah says (what means): {Mischief has appeared on land and sea by [reason of] what the hands of people have earned so He may let them taste part of [the consequence of] what they have done that perhaps they will return [to righteousness].} [Quran 30:41], in the same manner that good deeds reform morals, deeds, livelihood and the conditions of this world and the Hereafter.”
As regards giving details about all the deeds and actions that involve mischief, then this is difficult to mention in a fatwa, and you may find this in appropriate books.
Allah knows best.