Abandoning learning Arabic is a reason for becoming corrupt/deviated
Abu ʿAbdillah Muhammad ibn Idris ash-Shafi’ee 204 AH [May Allah have mercy on him] said,
ما فسد النَّاس إلا لما تركوا لسان العرب، واتبعوا لسان أرسطو
“People did not become corrupt [or deviated] except after their abandonment of the Arabic language and their inclination to the language of Aristotle!”
Source: Sharh Aqeedah al-Tahawiyyah 1/100; quoted by Imam Dhahabi in as-Siyar A’lam al-Nubala 10/74 and al-Suyuti in Sawn al-Mantiq p.15