Depends on the circumstance. It could be that the person you are trying to help believes they don't need it and that's why they aren't receptive of it. I clash with mum a lot on this - she sees me going about my day to day busy life and is forever trying to jump in, where it makes me feel incapable and useless.

I'm happy to make someone a meal, drive them somewhere should they need it, offer a friendly ear. But if it's clear it isn't needed or wanted then I leave it at that. Persistence is very annoying, especially if you're trying to stand on your own feet.