Faith — shraddha — is the ground on which every spiritual discipline stands. Krishna teaches in Chapter 17 that 'a person is what his faith is; as his faith is, so is he.' Faith in the Gita is not credulous belief; it is the deep inner conviction that orients the whole life, the settled trust in something larger than oneself. Every seeker acts on faith, whether he names it or not.
Surrender — sharanagati or prapatti — is faith's culmination. It is the moment when the seeker recognises that his own resources are not sufficient, and lets go into the Divine. The Gita's most famous statement of this teaching is the charama shloka of 18.66: 'Abandon all dharmas and take refuge in Me alone. I shall liberate you from all sins. Do not grieve.'
This verse is often called the essence of the Gita. It is not a repudiation of duty — Krishna has spent seventeen chapters explaining duty — but a recognition that even duty, done from ego, cannot finally liberate. The last step must be surrender. Only when the self-effort is offered up does the Divine grace complete what human striving began.
The Vaishnava traditions that grew out of the Gita — Sri Sampradaya, Gaudiya Vaishnavism, and others — built their entire theology on this teaching. Read these verses to see how faith ripens through the whole dialogue, until it becomes the wholehearted surrender that is also the doorway to freedom.