Why is Hijaab necessary in Islam?

Why Hijab is necessary in Islam?
Islam means obedience to Allah, obedience to Allah means having sincere faith in Him, such a faith means to believe in His power, belief in His power means recognizing and accepting His Majesty, accepting His Majesty means fulfilling the obligations laid down by Him and such fulfillment of obligations means actions.
Therefore, Islam does not mean mere faith but faith with actions and deeds.
Some sisters come up with the excuse that the non-believers laugh at them if they wear Hijab and they feel degraded. They may laugh for a little while but after some time, they will have no choice but to respect the Muslim women wearing Hijab for their discipline and principles which could not be shaken by their little laugh.
There are many Muslims sisters who are more concerned to please themselves and their non-believer friends than Allah (SWT). Let us not forget the purpose of our existence, which is to worship Allah and please Him. How can we worship and please Allah while we are disobeying Him and rejecting His command to please others
Many sisters have failed to understand the actual meaning of Hijab that can be summarized as follows:
Hijab is an act of obedience.
The hijab is an act of obedience to Allah and to his prophet (pbuh),
Allah said in the Quran : 'And tell the believing women to lower their gaze (from looking at forbidden things) and protect their private parts (from illegal sexual acts, etc) and not to show off their adornment except what must (ordinarily) appear thereof, that they should draw their veils over their bosoms.'(S24:31).
Hijab is IFFAH (Modesty).
Allah (subhana wa'atala) made the adherence to the hijab a manifestation for chastity and modesty. Allah says: 'O Prophet! Tell your wives and your daughters and the women of the believers to draw their cloaks (veils) over their bodies (when outdoors). That is most convenient that they should be known and not molested.' (S33:59). In the above verse (Ayaah), there is an evidence that the recognition of the apparent beauty of the woman is harmful to her. When the cause of attraction ends, the restriction is removed..
Hijab is Tahara (Purity)
Allah (swt) had shown us the hikma (wisdom) behind the legislation of the hijab: `And when you ask them (the Prophet's wives) for anything you want, ask them from behind a screen, that is purer for your hearts and their hearts.' (S33:53).
The hijab makes for greater purity for the hearts of believing men and women because it screens against the desire of the heart. Without the hijab, the heart may or may not desire. That is why the heart is more pure when the sight is blocked (by hijab) and thus the prevention of fitna (evil actions is very much manifested. The hijab cuts off the ill thoughts and the greed of the sick hearts.
Hijab is from Taqwah (Righteousness)
Allah (swt) says in the Qur'an: `O children of Adam! We have bestowed raiment upon you to cover yourselves (screen your private parts, etc) and as an adornment. But the raiment of righteousness, that is better.'(S7:26). The widespread forms of dresses in the world today are mostly for show off and hardly taken as a cover and shield of the woman's body. To the believing women, however the purpose is to safeguard their bodies and cover their private parts as a manifestation of the order of Allah. It is an act of Taqwah (righteousness).
Hijab is from Eemaan (Belief or Faith)
Allah (swt) did not address His words about the hijab except to the believing women, Al-Mo'minat. In many cases in the Qur'an Allah refers to the "the believing women". Aisha (RA), the wife of the prophet (pbuh), addressed some women from the tribe of Banu Tameem who came to visit her and had light clothes on them, they were improperly dressed: "If indeed you are believing women, then truly this is not the dress of the believing women, and if you are not believing women, then enjoy it."
The hijab is Haya' (Bashfulness)
There are two authentic hadith which state: "Each religion has a morality and the morality of Islam is haya'" AND "Bashfulness is from belief, and belief is in Al-Jannah (paradise)". The hijab fits the natural bashfulness which is a part of the nature of women.
hijab is from Gheerah feels jealous or protective over his wife or sisters and other-womenfolkfeels jealous or protective over his wife or sisters and other-womenfolk
The hijab fits the natural feeling of Gheerah, which is intrinsic in the straight man who does not like people to look at his wife or daughters. Gheerah is a driving emotion that drives the straight man to safeguard women who are related to him from strangers. The straight MUSLIM man has Gheerah for ALL MUSLIM women in response to lust and desire, men look (with desire) at other women while they do not mind that other men do the same to their wives or daughters.