Example sentences:

Ramayana: As secrecy was pivotal to Hanuman’s plan for finding Sita in Lanka, he waited till nightfall to have the cover of darkness. 

Mahabharata: Duryodhana was shattered by Karna’s death because Karna had been pivotal in his plan to defeat the Pandavas.

Bhagavad-gita: Bhakti is pivotal to the message of the Gita; those who marginalize it miss the thread that unifies its wide-ranging analysis.