While verse 6 might be a more oft-quoted verse than the one that precedes it, the real key to it all is tucked there in verse 5. The NIV translates it as "make the most of every opportunity," while the Phillips' translation reads "make the best possible use of your time." But both of those readings are weak when compared to the real language!
The Greek actually says, "redeeming the time," which is nearly the same word used in Galatians 3:13 - "Christ redeemed us from the curse of the law..." Isn't that wonderful? The idea of waking to a day and actively, by the power of Jesus, working to redeem even the time we're allotted? To even testify to the world about His goodness by the way a day passes through our hands, right here, right now?
Brothers and sisters, do you believe He can redeem even your time? Can a day such as this bear full witness to His glory?