I have a dear friend that has a hard time taking a compliment. When I tell her 'thank you,' she always says, "I don't know about that." And then I always say, "I know about it, and you're wonderful." She just laughs.
Consider the lilies. . . God made us all. We are not perfect, but we are wonderful. Let others tell you about your goodness, and take it in. It will help you smile inside.