Paul really wanted the Philippians to feel the joy he himself had through all his trials and sufferings. He even used the imperative mood (mood of command) when he said they should be glad and rejoice with him. Christ was 
God’s whole burnt offering for the sins of the world. Christ had to suffer! He had to die in order for our salvation to be secured. Like the drink offerings of the Old Testament, Paul saw his life as a mere libation added to the great sacrifice of Christ. He offered himself with great joy and encouraged us also to consider all our pains and sorrows as fellowship with the sufferings of Christ. In that way no pain is ever wasted and we too can find meaning and purpose in the miseries of life. Paul wants them to find joy through all their sufferings just like he did.
Then in Philippians 2:19, Paul goes back to the things that bring him real joy in life. He and Timothy were on the team that planted the Church in Philippi years before. They knew Timothy well and Paul intended to send him to them knowing how they will be glad to see him again. But he adds a thought when he writes, “I hope in the Lord Jesus to send Timothy to you soon, so that I too may be cheered by news of you.” They will be cheered upon seeing Timothy again, and Paul himself will be cheered when Timothy returns to Rome with news about how things are going in Philippi.
Paul is expecting the Best! I love this man! He knows of the struggles and divisions in the church and he addresses the need for each and every one, along with the elders and deacons, to cultivate the mind of Christ in all their dealings with each other. He expects them to receive his instructions with open and willing hearts. He expects the two women who had brought division and animosity to respond well. He expects the best from them! We don’t give our best to those who expect us to fail! We don’t get the best from those we expect to fail. It’s nearly a self-fulfilling prophecy. Christ teaches us to expect the best, but always be ready to forgive and restore when someone fails. We all do, and we all will again. So will others around us. I love what Max Lucado said in “No Wonder They Call Him The Savior.” He writes, “Expectations alone are the bullets that can kill; but buffered by acceptance and forgiveness, they can bring out the best.”