Arjuna raises a new concern, and it is one of the most poignant questions in the entire Gita. Suppose someone has faith — genuine, heartfelt faith. They set out on the path of yoga. But somewhere along the way, effort falters. The mind wanders and does not come back. Perfection is not reached. What happens to that person?
The question matters because it describes most seekers. Very few walk the path to its end in a single lifetime. Most of us begin with sincerity, practice for a while, get pulled away by life's demands, and leave the journey incomplete. Arjuna is asking on behalf of all of them.
Notice the combination: faith is present ('shraddhayopetah'), but sustained effort is not ('ayatih'). The heart was willing. The follow-through fell short. Is such a person lost?