The primary purpose of Tasawwuf is the reformation of the actions of the heart.
Source, in full
Amir Bashir (December 2015). Muhammad Anwar Khan Qasmi (ed.). "Deobandi Sūfi Doctrine: Towards a Comprehensive Understanding of Tasawwuf within the Context of Tawhīd and Sunnah". Islamic Literature Review. Deoband: Deoband Institute of Islamic Thought. 2 (2): 3.