Week 6 of the study involved the role of "calling" as a tool in evangelism. This series has dealt with the implications of living out your faith every day of the week, which means treating work as an extension of faith. It's not just that work is something separate from the life you lead on Sunday morning, but it should be an integrated part of that whole. Since sharing the gospel is the highest privilege and responsibility in the life of faith, work must also be an integrated part of evangelism.
In particular, the idea of "calling" can be useful in evangelism. It's something that a lot of people will find familiarity with, even if they don't understand it in the way that Christians understand it. (Well, to the degree any of us even understand it.) Just like Paul taking the altar to the unknown god and turning it into a vehicle for the gospel, so we should use calling to find and reach people where they are.
Frank has said that this was the entire basis of his thesis, which was itself the basis for this series. It's sound advice. If you believe that God is reaching out to every person, the way a person wrestles with purpose and calling can definitely be an opening for the gospel. They hear God, even if they don't understand it. (Or, in Paul's words, "Therefore what you worship without knowing it, this I proclaim to you.")
This is probably much more complicated in practice, though. This area runs up to a problem Christians have been having since New Age spirituality became so prevalent in the West, in that the language used by Christians has been co-opted to mean something almost, but not quite, entirely unlike it's original meaning. The shared language doesn't just extend to the idea of a calling, but to what that should mean as well. Most of the world understands morality through the lens of "good deeds;" it doesn't matter what you believe, as long as you're a "good person" who does "good deeds." The "calling" a person wrestles with then becomes a matter of finding something you enjoy doing and/or being able to do "good deeds" through it. It's not entirely divorced from the ideas we've been discussing the last several weeks, but it's certainly a bastardized version of it.
The heart of the matter is that our calling is God inviting us to participate in his work. Expressing that to a world that wonders whether such invitations are possible . . . well, that's the hard part. I'm not really sure I have anything profound to add that wasn't already said by Frank in this series. Avoiding formulas. Listening. Humility. Explaining ourselves. Everything that evangelism is supposed to be.