The limit, which if a person exceeds is considered immoderate, is exceeding the Mashru` (Islamically lawful) means. Immoderation is to adopt the pedantic perspectives in studying issues of little importance deeply and pretentiously. The Prophet (peace be upon him) forbade this inclination saying:
Beware of immoderate religiousness, for those before you were destroyed due to their immoderate religiousness.
(Related by Ahmad and others with an authentic Sanad 'chain of narrators'). Negligence is to slight the commandments and prohibitions by committing acts of disobedience such as Zina (sexual intercourse outside marriage), Ghibah (backbiting), Namimah (calumny), etc., or by neglecting acts of obedience such as being dutiful to someone's parents, maintaining the ties of kinship, and answering the greeting.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.