Enquire about things before taking action , take action only if are dead sure about the truth , or else you may cause harm

Surah Hujrat Verse 6.

O believers! If some wicked person brings you any news, inquire thoroughly into its truth (lest) you should cause (undue) harm to a people unknowingly, and later feel regret for what you have done.

When two parties of Muslims fight , reconcile between them

Surah Hujrat Verse 9.

. And if two parties of the Muslims fight, make them reconcile. Then if either of these (parties) commits injustice and aggression against the other, fight against (the party) that is committing aggression till it returns to Allah’s command (of establishing peace). When they revert and submit, make peace between them with equity. And put justice to work. Surely, Allah loves those who do justice.

Surah Hujrat Verse 10.

The truth is that (all) believers are brothers (to one another). So make peace between your two brothers and always fear Allah, so that you may be shown mercy.

Dont make fun of others and avoid ridiculing others

Quraan (Sura al-Hujurat, Verse 11)

O believers! Let no community ridicule another community. It is likely that they may be better than those (who ridicule). Nor should women make fun of other women. It is likely that they may be better than those (who make fun). And do not offend or find fault with one another, nor call each other names. Calling someone wicked or indecent after (he embraces) faith is an extremely evil name. And those who do not turn to Allah in repentance, it is they who are the wrongdoers.