To Live Is Christ

Paul in his letter to the church at Phillipi has just finished telling them about his circumstances in his life and how he knows God is going to use them for the furtherance of the Gospel and now we come to this passage here in Philippians 1:19-26 where Paul makes the statement "To live is Christ" What exactly does that mean? It's a rather interesting phrase, but Paul saw something intrinsic about Christ and his life. What was it? The way Paul lived his life brought him peace and joy in the midst of difficult circumstances. How can we do the same?