अप्रकाशोऽप्रवृत्तिश्च प्रमादो मोह एव च ।
तमस्येतानि जायन्ते विवृद्धे कुरुनन्दन ॥ १४.१३ ॥

aprakāśo’pravṛttiś-ca pramādo moha eva ca |
tamasy-etāni jāyante vivṛddhe kuru-nandana || 14.13 ||

Predominance of tamas is marked by ignorance, dullness, inactivity, inattention and delusion.

With Krishna’s enumeration as the yardstick, it becomes helpful and easy for a discerning seeker to know where he stands with respect to each of the guṇas in him. After assessing the situation, the seeker must strive consistently to elevate himself to generate an abundance of sattva. For this, he must first reflect upon the characteristics of the respective guṇa and then consistently and diligently work towards achieving a preponderance of sattva in him.

This is the greatness of the Bhagavadgītā. It verily describes the full-fledged course of sādhanā. It enables the sādhaka to know where he stands and where exactly he should reach. It also prescribes the requisite way or means to reach the destination.