These first lines of Paul's Letter to the Philippians are like a song, a song of praise. He sings of joy and confidence at a time when his converts at Philippi were becoming divided among themselves because of factions festering among them.
The time Paul wrote this letter he himself was in prison, suffering great pain both physical and mental. The thought of his faithful Philippi converts was his consolation, and his affection for them eases his suffering.
He encourages them to persevere, that the good work begun in them may not be wasted but come to its joyful fulfillment in the day of Christ. He encourages them to value those things that really matter in life: love for one another, a clear conscience and blameless conduct.
Paul in his letter is also encouraging us in our dark moments when we seem to be alienated from friends and family, divided in ourselves and from others, to remember the things that really matter in life - the love of Jesus that binds and heals.
Lord our God, we pray that the good work You have begun in us through our baptism, nourished by the Eucharist, may bring us to the joy of Your promise.