How to help?

How to help those that don't want to be helped? This question has increasingly bothered me for some years now, on both a personal and more global level.

When growing up, my mother was the person I could not help when she needed it - and denied it - most. As a twentysomething, it was a fallen Russian that I could not save from himself. Now, at thirty, I find that I cannot help my husband and father-in-law reunite, and I cannot help my brother create happiness within himself. Perhaps this all sounds obvious, and maybe familiar, to readers, but I may never come to terms with the fact that people resist so strongly to finding love in their hearts and sharing it with others when, in fact, that is the very thing all humans need and desire most.

But how to accept one's inability to help those one loves? And is it something we should even accept?