Here is the audio and notes from Sunday morning. I hope it helps. Everything is free. Here's the description:
"Do not lie." If your like me, that is probably the least important commandment. But to Christ, our integrity is a gospel issue. If people don't believe me when I speak of earthly things, how will they believe me when I speak of heavenly things? Jesus comes to set the record straight.
Bonhoeffer: Truth and the Cross