Those who seek worldly knowledge must:

*    First, learn necessary Islamic knowledge.

*    Only study subjects that do not contradict the Quran, Hadith, or Islamic teachings.

*    Completely avoid subjects that contain anything against Islam.

*    Maintain Islamic manners and appearance while studying worldly knowledge.

By fulfilling these conditions, learning permissible worldly knowledge is allowed.

3) Whomever Allah wills good for

The final Prophet of Allah صَلَّى اللهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم said:

مَنْ یُرِدِ اللہُ بِہٖ خَیْراً یُّفَقِّہْہُ فِی الدِّیْن

Whomever Allah wills good for; He grants them understanding of the religion.^[1]

4) Scholars are the inheritors of the noble Prophets عَـلَيْـهِمُ  الـسَّـلاَم  

Kathīr b. Qays رَحْمَةُ الـلّٰـهِ عَـلَيْه narrates:

I was in a masjid of Damascus in the presence of Abū Dardāˈ. A man arrived and said, “O Abū Dardāˈ! I have heard you narrate a Hadith of the Prophet صَلَّى اللهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم. I have come from Medina to learn this.”

Abū Dardā رَضِىَ اللّٰهُ عَـنْهُ asked, "Have you come for business?" The man said no.