Though it's not "good form" to begin a biblical commentary by mentioning what a text doesn't say, it might be necessary to do so in the case of today's gospel pericope.
Our well-known Martha/Mary story wasn't created by Luke to highlight the superiority of the "contemplative" life over the "active" life. Mary isn't the forerunner of contemplative, cloistered religious who've chosen a better way to live their faith than those Marthas who are immersed in the active ministry. No evangelist would have understood the distinction between those two lifestyles. Luke is simply telling his gospel community that, following Mary's example, even women can become active disciples of Jesus.
But even more than that, Luke is demonstrating what can happen when people practice one of Scripture's classic ways of demonstrating their commitment to God: hospitality.
As far back as Abraham and Sarah - the first Jews - people of faith were expected to be hospitable to strangers. In offering food, drink and rest to three travelers, this special couple discovers they're actually taking care of Yahweh. (The "three" certainly aren't the Trinity. Our Genesis author is simply saying no one human depiction of Yahweh can encompass all of God's otherness; like children, when drawing pictures of their parents, always make them larger than the other people they depict to show their importance in their lives, our sacred authors also "expand" Yahweh.)
Biblical writers are convinced that no one can welcome strangers into their lives without surfacing things they've never before noticed or experienced. A generous act also brings blessings and changes to the actor. In the case of Abraham and Sarah, they're going to become parents. The child for whom they longed for years is now just nine months away.
In the case of Martha and Mary, an act of hospitality to an itinerant preacher on his way to Jerusalem brings about a total change in the direction of their lives. Martha's chided for not being able to see beyond people's expectations of her; Mary's praised for stepping outside her accepted gender role and actually opening the door to the possibility of becoming another Christ. Had the sisters waited for someone else to step up and care for this Galilean carpenter, their lives would no doubt have been smothered in mediocrity. When they opened their home to Jesus, they also opened themselves to experiencing a brand new life.
Along the same line, the follower of Paul who composed Colossians reflects today on what happened when the church opened its doors to 99% of the human race.
As far as we can tell, first generation Christians evangelized only Jews. After all, their mentor, Jesus, was a Jew who instigated a Jewish reform. Why would Gentiles be interested in a Jewish movement? But the writer's mentor, Paul, not only was able to experience the risen Jesus even in those who were outside the "true" faith, but eventually came to realize that God actually wanted "the riches of his glory" to be made known to these Gentiles. The risen Jesus could be embedded in them just as much as he/she was embedded in Jews who had committed themselves to imitating his dying and rising. By opening the door to Gentiles, as Gentiles, Paul and his followers began to understand their faith and their ministry from a totally new perspective.
Yet, as our author states, openness is always accompanied by suffering and affliction. Among other hardships, we'll have to struggle with those who contend we should keep our doors shut and let well enough alone. Opening doors to those who are different will certainly cause pain. Just ask the Boy Scouts.