When we read this story, we have to remember that it's not meant to discourage us from serving. Martha's serving is fine -- hospitality was vital in their culture. The drawback is that she is distracted. She is anxious. She is so caught up in the tasks that she is missing the larger picture of who and why she is serving. Her tasks have become overwhelming her and she is exhausted.
When we focus on Jesus first, our fears should diminish. We worry less about being unprepared and unqualified. We worry less about appearing unworthy. We realize that in Christ, we are enough, and that helps us find rest, even in the midst of busy-ness and numerous tasks. We find ways to be with Jesus, to trust in Christ, even while we serve.