Want to know how to behave properly? Then you should be

Don't make fun of people

"O you who believe! let not (one) people ridicule (other) people perchance they may be better than they, nor let women (ridicule) (other) women, perchance they may be better than they;" … 49:11

"…And neither shall you defame one another…" 49–11

"…nor call each other by (offensive) nicknames: Ill-seeming is a name connoting wickedness, (to be used of one) after he has believed: And those who do not desist are (indeed) doing wrong." 49–11

No spying or gossiping is allowed

"…And spy not, neither backbite one another. Would one of you love to eat the flesh of his dead brother? You abhor that (so abhor the other)! And be conscious of Allah! Allah is Relenting, Merciful." 49–12

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Be fair no matter what

"….but if one of them acts wrongfully towards the other, fight that which acts wrongfully until it returns to Allah's command; then if it returns, make peace between them with justice and act equitably; surely Allah loves those who act equitably." 49:9

Always verify all kinds of news before reacting

"O You who have attained to faith! If any iniquitous person comes to you with a [slanderous] tale, use your discernment (verify it), lest you hurt people unwittingly and afterward be filled with remorse for what you have done." 49:6