Is a person rewarded for diligence or for action only, and how can one dedicate their work sincerely to God while having a personal goal?

The intent behind "Ijtihad" is not clear. If it refers to diligence in inventions, innovations, martial arts, and sports, then its ruling reverts to the ruling of these matters themselves. However, if it refers to diligence in acts of obedience and worship, then one is rewarded for it. And if it refers to jurisprudential Ijtihad, then one is rewarded for it if they are qualified for it. To make one's work for the sake of Allah while striving towards a goal, let the goal be the benefit of Islam and Muslims, and seeking reward from Allah.