Passive vocabulary is more important than active vocabulary.
Just to be a bit of contrarian, I believe that passive vocabulary is more important than active vocabulary. Passive vocabulary is the focus of most of my active language learning. If I have a large vocabulary, the rest will come.
For me, it is more important to understand, to encounter words often in meaningful, and therefore credible contexts. I find it less useful to produce, with great difficulty, a small number of artificial phrases and sentences using my new words, at a stage when I have little familiarity with the language. This is time I would rather spend reading and listening.
I am only now at the stage in Czech where I can have an intelligent conversation, albeit with gaps and hesitations. But I at least have words, passive words, so I can understand what is said. I am also finding that I am able to retrieve more and more of these passive words and phrases when I want to speak. This is after one year.