As you read through Philippians, be on the lookout for words of "joy" and "rejoicing." There's a reason this book is called "Paul's Epistle of Joy!"
We even see a hint of that in the middle of chapter 1 as Paul reflects on his uncertain future. In vs. 19-26, Paul considers that he may be getting ready to leave this world. He is in prison, but that hasn't diminished his sense of joy. He knows that he will be either departing to be with Christ, or remaining to continue his work in the gospel. While he doesn't know which it will be - coming or going - he is content with either outcome.
Paul has arrived at that place of utter trust in the Lord where he recognizes that God's plan, whichever way it is, will be all right with him. That peace is something all of us can strive for!