Bhagavad Gita, Chapter 17, Verse 28

Whatever is sacrificed, given or performed, and whatever austerity is practised without Shraddhâ, it is called Asat, O Pârtha; it is naught here or hereafter.

The chapter closes by naming the real opposite of everything just explained, action done without faith at all.

Krishna doesn't end on a positive note alone, he names the real cost of skipping faith entirely, no benefit here or beyond. That direct contrast is what closes the whole discussion.