Bhagavad Gita Chapter 3.32
ye tv etad abhyasūyanto
nānutiṣṭhanti me matam
sarva-jñāna-vimūḍhāḿs tān
viddhi naṣṭān acetasaḥ
Translation
But those who, out of envy, disregard these teachings and do not follow them are to be considered bereft of all knowledge, befooled, and ruined in their endeavors for perfection.