We’re all waiting on something.  There’s where we are and there’s what we’re waiting for—whether it’s someone to arrive or some date to come.  For the Thessalonian church, they were waiting for the return of Jesus.  “…to wait for his Son from heaven, whom he raised from the dead—Jesus, who rescues us from the coming wrath” (1 Thessalonians 1:10).  Paul writes to them “while they’re waiting,” and instructs them on what they ought to be doing “in the meantime.”