In plain words
Rāmakṛṣṇa Paramahaṃsa, Jayadeva, Gaurāṅga, Tukārām, Tulasīdās, Rāmadās, Kabīr Dās, Śāradā Devī, Mīrā, Sakkubāī, Mallamma and others had little outer schooling, yet today people of every religion, every community and every country the world over worship and honour them; the root cause is their self-confidence joined with ‘purity of citta’. True Vidyā is what brings purity of citta.