A friend lost a friend to an accident and I told him this:
The only thing you can do now is take the best of him out into the world. You can be more like what you admired in him. And when you see someone such as your kids or especially HIS kids act like something you admired in him, you can say "you remind me of . . . ” and tell them why and tell them a little story about him. Everyone knows him in different ways and you have to figure out what specialness about him you know and that others need to know and figure out a way to give that to them. You are the only keeper of that thing, of the special things you know about him, and they will not know it of him unless you give it to them. That is the only way we keep people alive and living on this earth and keep their contribution flowing through the generations to come. Not just by remembering the person, but by giving voice to those remembrances and in such a way that it encourages in others the good you saw in the friend you lost.