In the light of the explanations above, modesty can be divided into two categories: an innate or instinctive feeling of shame, which prevent people from engaging in what is considered shameful and indecent, and modesty originating in belief, which constitutes an important, deep dimension of Islam.
Combining the instinctive feeling of shame with modesty based on Islam forms the greatest safeguard against shameful or indecent acts. Alone, each one may be diminished or utterly lost. If this innate feeling of shame is not combined with awareness coming from belief and expressed in verses like: Does he not know that God sees (all things)? (96:14) and consciousness of God's constant oversight: God is ever watching over you (4:1), it cannot last long, for its endurance depends on belief. This essential relation between modesty and belief was expressed by God's Messenger, who told a Companion after hearing his advice on modesty to another man: Leave him, for modesty comes from belief.  He also said: Belief has seventy or so divisions. Modesty is a division of belief. 
We may conclude from these Prophetic sayings that like other seeds of innate virtues, one's natural feeling of shame develops to the extent it is strengthened with the forces and means that produce knowledge of God. It then becomes a dimension of one's spiritual life, an obstacle against the carnal self's excessive desires. If this feeling is not reinforced and developed with belief and knowledge of God or strengthened with consciousness of God's constant oversight, and left to dissipate in sensual or carnal pleasure, one will witness in an individual or a community those indecencies and perversions that make anyone truly human ashamed of being human. The glory of mankind and the perfect example of modesty, upon him be peace and blessings, said: If you have no modesty, do whatever you wish. 
The words haya (modesty or feeling of shame) and hayat (life) come from the same root. This signifies that modesty is a sign of a lively heart, and that a heart's liveliness depends on its owner's belief and knowledge of God. If a heart is not fed continuously with belief and knowledge of God, it is almost impossible for it to remain lively and give rise to modesty.
According to Junayd al-Baghdadi, haya means awareness of God's bestowed material and immaterial bounties, and consciousness of personal defects and faults. Dhu al-Nun al-Misri holds that haya means that one constantly feels shame in his or her heart on account of personal sins and offenses, and is therefore careful about his or her actions.  Another spiritual master defines haya as never forgetting how God treats one and ordering one's life according to the fact that God sees all that is done and thought.
It is recorded in al-Qushayri's Al-Risala that God declares: O son of Adam! So long as you maintain your modesty and feeling of shame before Me, I make people forget your defects.  The Lord of Might and Dignity also said to Jesus, upon him be peace: O Jesus, first advise your own selfhood. If it accepts your advice, then you may advise others, or else you must feel ashamed of yourself before Me.
Some have mentioned different categories of modesty or shame. For example, the shame or modesty felt by:
- Adam, who felt guilty until he was forgiven.
- Angels for their heartfelt incapacity to give due worship to God, as expressed in their saying: Glory be to You! We are unable to worship You as Your worship requires, although they glorify Him day and night without stopping.
- Gnostics or those distinguished with knowledge of God in the face of His Majesty, despite their profound knowledge of Him, which they express as: Glory be to You! We are unable to know You as Your knowledge requires.
- The spiritually advanced when in awe of God, although they never give in to their carnal desires and ambitions.
- Those distinguished with utmost conviction of God because of their supposed distance from Him, although they always feel His infinite nearness despite the infinite distance of humanity from God Almighty.
- Lovers of God who feel disloyalty arising from their anxiety over not being able to love God as His love requires.
- Those who feel a lack of sufficient sincerity and do not know for what they must pray to God.
- Those exalted ones who are conscious of the fact that they, as human beings, have been honored with the fairest creation, because of the base acts of which they accuse themselves and which, according to them, are irreconcilable with being part of the fairest creation.
The first degree of modesty is to see oneself with the sight of God. That is, the person practices self-control or self-supervision according to God's standards. This practice engenders a feeling of shame or modesty that produces extreme caution in thoughts and acts. Such a degree of modesty is found in people considered lively on account of their feelings and thoughts.
The second degree is proportional to one's awareness of nearness to God, and the feeling of always being in His Presence. This can be experienced by those who are always conscious of the meaning of: He is with you wherever you may be (57:4), about which the Prophet, upon him be peace and blessings, said:
Be as modest before God Almighty, as the necessity of being modest before Him requires. Let him who is blessed with this degree of modesty always control his mind and its contents, as well as his stomach and its contents. Let him always remember death and decay after it. One who desires the afterlife will renounce the adornments of the world. One who is able to do that can feel as much modesty before God as the necessity of being modest before Him requires. 
One can reach the third degree by deeply feeling the absolute Divine disposal of all things, by living a life of profound spirituality in pursuit of the final destination: And in your Lord is the final goal (53:42). The effort to reach this final goal continues throughout a whole life dedicated to following the path to Him.
One's degree of modesty determines one's true humanness. If a traveler cannot order his or her life and discipline his or her acts according to the demands of the eternal life and to live in utmost humility and modesty, then his or her existence is a personal shame and a burden to others, as stated in the following couplet:
By God, there is good neither in life
Nor in the world when modesty disappears.
Modesty is a Divine quality and mystery. If people knew to whom it essentially relates, they would act more carefully and sensitively. To illuminate this point, it is related that
God Almighty asks an old man on the Plain of Resurrection to account for his acts in the world: Why did you commit such and such sins? The old man denies that he had done so. So, the Most Compassionate of the Compassionate commands the angels: Take him to Paradise. The angels want to know why the Almighty has commanded so, although He knows that the old man committed those sins. The Almighty answers: I know, but I looked at his white beard as one belonging to the Community of Muhammad and felt ashamed to tell him that I knew he was lying.
As recorded in Kanz al-'Ummal, when the Archangel Gabriel told this to God's Messenger, upon him be peace and blessings, the Messenger's eyes filled with tears and he said regretfully:
God Almighty feels ashamed to punish those of my Community whose beards have turned white, but those of my Community with white beards do not feel ashamed to commit sins. 
To sum up:
Hayiy (All-Modest) is one of the Divine Names,
So strive and acquire modesty.
 Abu Dawud, "Sunna," 14; Nasa'i, "Iman," 16.
 Al-Buhkari, "Anbiya'," 54; Abu Dawud, "Adab," 6; Ibn Maja, "Zuhd," 17.
 Al-Qushayri, Al-Risala, 215.
 Ibid., 216.
 Ibn Hanbal, Musnad, 1:387.
 Nasa'i, "Sahw," 60.
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