Paul backs up his appeal for the Philippians to treat each other well by quoting an early Christian hymn known to them from their Sunday gatherings.
In these lines we are delving back behind even the letter itself to an earlier stage in the emergence of early Christianity.
This was presumably a song that Paul taught them while first explaining what it means to be a Christian. More than that, we can presume the song to have originated in the Christian community at Antioch where Paul himself first became a Christian.
These words we focus on today take us back very close to the start of Christianity.
Interestingly, Paul does not ask people to believe a long list of things about Jesus, but to act in the same way that Jesus acted.