The words khalq (creation) and khuluq (nature) are derived from the same root word. Khalq relates to the external form or appearance, the visible, material, and experienced dimension of existence; khuluq is concerned with the spiritual dimension, meaning, or content. An individual cannot be judged or known by his or her outer appearance, for one's real identity lies in one's character, temperament, and natural disposition. However many different images one may project; one's true character or temperament eventually will reveal itself. How meaningful are the following words of an Arab poet of the pre-Islamic Age of Ignorance:
If a man has a bad quality, sooner or later it will reveal itself;
Let him continue to think that it can remain hidden.
In other words, the outer appearance is deceiving, for one's natural disposition removes or corrects all deceptions and thereby reveals one's true nature. Since one may acquire a second nature through education and habituation, moralists divide nature into good and bad. In the present context, we use "nature" to mean "good nature."
The most correct standard of a good spiritual life, one that Sufism uses to describe or qualify a person, is good nature. One who has taken a few steps forward in good nature may be regarded as advanced in the spiritual life. Although miracles, dazzling stations, and superhuman actions may be acceptable when they issue from good nature, they are worthless if not combined with good nature.
When asked which believer was better on account of his or her belief, the Prophet Muhammad, upon him be peace and blessings, answered: The one who is better in conduct or nature.  This is natural, because God praises and consoles His most distinguished servant the Prophet Muhammad, upon him be peace and blessings, not with His extraordinary favors but with his laudable virtues and praiseworthy qualities, declaring: You stand on an exalted standard of character (68:4). His nature was the aim and fruit of his creation. Since the Prophet's conduct embodied Islam and the Qur'an, when his wife 'A'isha, may God be pleased with her, was asked about his conduct by Sa'id ibn Hisham, she answered: Do you not read the Qur'an? His conduct is (the embodiment of) the Qur'an. 
The verse: You stand on an exalted standard of character (68:4) shows that the incomparable conduct of the Prophet, upon him be peace and blessings, was based on the Qur'an. In addition to his outer and inner faculties and senses, and the material and immaterial aspects of his creation and character, the Prophet, upon him be peace and blessings, was endowed with all potentialities needed to be the most forward and greatest representative of human virtue. Developing these potentials to the highest degree possible, he attained the highest degree of human perfection.
Not content with this state, as is declared in the verse: Surely, in the Messenger of God you have a good example for him who hopes for God and the Last Day, and remembers God much (33:21), he established the most excellent example for his followers and thereby gradually transformed them into the most virtuous community of all time. With such sayings as: The most perfect in belief among the believers are the most perfect in conduct ; A man can "cross" with good conduct the "distances" which he cannot with acts of worship and adoration ; and: The first virtue to be weighed in the Balance (in the other world) is good conduct,  and by employing the perfect, fruitful principles he brought to perfect humanity, he guided his followers to the realms where angels move.
The signs of good nature have been summarized as follows: a person possessing this quality does not hurt anybody by either word or deed, overlooks those who hurt him or her and forgets the evils done, and returns evil with good. The Prophet, upon him be peace and blessings, who is praised with the verse: You stand on an exalted standard of character (68:4), is the most excellent example of these virtues. He was not offended by the one who stood before him and told him to be just,  by the one who pulled his robe from the back and hurt him,  by the one who threw dust on his head and insulted him, or by the one who slandered his innocent and beloved wife 'A'isha.  In fact, he visited each of these individuals when they became ill  and followed their funeral processions. He did so because good nature was a dimension of his blessed existence.
Many people seem to be good natured, mild-mannered, and humanitarian, although good conduct and mildness are no more than affectations. When they experience a little irritation, anger, or harsh treatment, their true nature will be revealed. One who has good nature does not change his or her manners even when in a hellish state, but remains mild and shows no harshness. A heart open to good nature is like a very broad space in which one can bury one's anger and rage. As for those intolerant and impatient ones who display bad conduct, they are, like Cain, more stupid than the raven, and can find no place to bury their anger, hatred, and ill feelings.
Let us conclude this discussion with the following couplet:
It is by good nature that a man can be perfected;
It is by good nature that the order of the world is maintained.
 Muslim, "Musafirin," 139.
 Abu Dawud, Sunan, 14; Ibn Hanbal, Musnad, 2:250.
 Al-Haythami, Majma' al-Zawa'id, 8:24.
 'Ala al-Din 'Ali al-Muttaqi al-Hindi, Kanz al-'Ummal fi Sunan al-Aqwal wa al-Af 'al, 8 vols. (Beirut: 1985), hadith no. 5160.
 Al-Bukhari, "Adab," 95; Muslim, "Zakat," 142.
 Al-Bukhari, "Khumus," 19; Muslim, "Zakat," 142.
 Al-Bukhari, "Shahada," 15; Muslim, "Tawba," 56.
 Abu Dawud, "Jana'iz," 1.