A person may ask:” Does crying for the dead contradict patience? Is it a symbol of grief that contradicts faith and believing in God?
God almighty has existed the behavior of crying, not over crying, as a gift for His servants to calm them and relieve their pain. Therefore, God cannot prohibit them from crying unless it doesn’t be extravagant and lead him to the level of grief that contradicts patience and trust in God almighty and His fate.
Therefore, it was narrated that the prophet Muhammad (pbuh) has cried for the death of his son Abraham and said:” O Abraham, we are sad for your death but patient. The heart is sad, eyes cry, but we don’t say what angers God”. 
This is the important point. A faithful man, no matter how great the distress is, should be patient and not anger God almighty by his tongue or behaviors.
In some stories, Mansour Al Sayqil says:” I complain my insane sadness for the death of my son to Al Imam Al Sadeq (a.s), so he said:” If you face a distress, cry; for it relieves you”. 
Crying in general is not forbidden, but crying in a way that leads a man to lose his patience or show him as a sad and compliant man who doesn’t accept God’s fate is what is forbidden. Therefore, in the stories of Ahl Al Bayt, lapping the face and chest, and tearing the clothes into pieces are forbidden. When Jabir bin Yazid Al Ja’fi asked Al Imam Al Sadeq about grief, he said:” The worst grief is yalleding with woe, mourning, and slapping the face and chest…” 
Amro bin Al Mikdam says: “I heard abi Jaafar (a.s) saying:” Do you know what God almighty meant when saying: ”They don’t disobey you in any honorable thing”?, I said no. He said:” The prophet Muhammad (pbuh) said to Sayyeda Fatima (a.s):” When I die, neither scratch your face, free your hair, mourn, nor weep”. Al Imam abo Jaafar said:” This is the honorable thing that God almighty talked about”. 
This shows that among a man’s role is to enjoin his family the good and help them not to freak out through screaming, mourning, and slapping chests… Therefore, it was narrated that when Al Imam Ali (a.s) came to Al Kufa, after the Souffin battle, he heard the Syrians mourning for the dead of Souffin, so he said to Sharhabil Al Shami:” Do your women make you helpless? Can’t you stop them from doing these sounds (he meant the sound of screaming).
Here, we should take into consideration that a wise believer should pay attention to details, even in the greatest distresses. He should behave politely and teach politeness to his family members. God almighty says:” O believers! Protect yourselves and your families from a Fire whose fuel is people and stones”. 
Help your Dead, Al Maaref Islamic and Cultural Institution
 The Means (Al Wasa’il), part 3 page 280
 Al Kafi, part 3, page 250
 Al Kafi part 3, page 222
 Same source, part 5, page 527
 Nahj Al Balagha, part 4, page 77
 Surah Al Tahrim verse 6