In the Name of Allah, The Most Gracious, Most Merciful
Sibghah (trait) and Fitrah (man's innate disposition):
Praise be to Allah, The Lord (The One and Only) of the Worlds, and blessings and peace be upon our Master Muhammad, the Truthful and the Faithful.
The exact meaning of Fitrah is to incline towards the truth, but it does not mean that you are truthful. Fitrah is to like trustworthiness, but it does not mean that you are trustworthy, this is Fitrah. Fitrah is to like justice, but it does not mean that you are just. Take for example a gang of thieves who robbed a house, one of them would say, "Distribute the loots justly!" Thus, Al-Fitrah is a psychological structure that accords with Share' (Islamic Law).
﴾ Allah's Fitrah (i.e. Allah's Islamic Monotheism), with which He has created mankind. ﴿
Every person on earth loves perfection, but he might not be perfect, so this is Fitrah. Sibghah, on the other hand, is when this person becomes perfect. In other words, loving justice is Fitrah, whereas being just is Sibghah, and loving trustworthiness is Fitrah, whereas being trustworthy is Sibghah.