According to the īśā Upaniṣad and the latter Śrī Śaṅkarācārya (of Advaita) commentary:
अन्धं तमः प्रविशन्ति येऽविद्यामुपासते । ततो भूय इव ते तमो य उ विद्यायां रताः ॥
andhaṃ tamaḥ praviśanti ye'vidyāmupāsate | tato bhūya iva te tamo ya u vidyāyāṃ ratāḥ ||
(Isha-Upanishad, 9th Mantra)
‘They enter into blinding darkness who worship avidya(rites); into still greater darkness, as it were, do they enter who delight in vidya(meditation).’`
It goes on to say in commentary:
Who? Ye they on the other hand who giving up rites; vidyayam u ratah, are engaged only in vidya are always bent on the meditation (and worship) of gods.
Please also explain what the darkness is. I would preface to say I have an understanding of Advaita and the concept of liberation in this lifetime but it was from my previous understanding that liberation is the goal of Hinduism in its entirety including all sects; please forgive me if wrong and please forgive my sanskrit as am quoting from a book on the second block quote.