108 important slokas from Bhagavad Gita
They typically cover:
1. The nature of the soul (ātma-tattva)
2. The nature of God / Supreme Being
3. The nature of the world (prakṛti, guṇas, māyā)
4. The path of liberation (mokṣa)
5. Pure devotion (bhakti)
Final conclusions (siddhānta)
The Gita repeatedly narrows down to bhakti as the ultimate solution.
Because the Gita is 700 verses, people traditionally choose a smaller set that captures the entire essence.