Two paths. Two outcomes. Krishna lays them out with complete clarity. Fix your mind on Me, and by My grace you will sail across every difficulty — no matter how large, no matter how many. That is one path. The other: if ego stops your ears, if pride makes you refuse to listen — you will be destroyed.
The image is of a river crossing. On one side stands the person willing to take refuge. On the other stands the person clutching their own certainty so tightly that they cannot reach for help. The river does not care which bank you choose — but the current is real.
There is both tenderness and firmness in Krishna's voice here. He is not threatening Arjuna. He is being honest with someone he loves. A doctor who tells a patient the consequences of ignoring treatment is not being cruel — they are being truthful.