What is the name/adjective of a human who doesn't believe in God but s/he is honest and does good in his/her life?

In Islamic terminology, a person who does not believe in God is typically referred to as a "disbeliever" or "kafir." However, the Qur'an acknowledges that a person's actions can be evaluated independently of their beliefs. For instance, the Qur'an emphasizes the importance of goodness and sincerity in one's actions.

In Surah Al-Lail, it is mentioned: And believeth in goodness; 92:6. This verse indicates that belief in goodness and the performance of good deeds are significant, regardless of one's belief in God. Additionally, in Surah Al-Hujuraat, it states: The (true) believers are those only who believe in Allah and His messenger and afterward doubt not, but strive with their wealth and their lives for the cause of Allah. Such are the sincere. 49:15. This illustrates that sincerity is a key quality that defines a true believer.

While there may not be a specific term in Islamic theology for a non-believer who is honest and does good deeds, their actions can be recognized as commendable, and they may be viewed as possessing qualities of sincerity and goodness. The emphasis is placed on the individual's actions rather than their belief alone.