Welcome to Philippians!
What was on Paul's heart as he wrote this letter to his friends in Philippi? If you read through his letter in one sitting several times, you will see some key themes, some things that were very important to Paul, very much on his heart as he communicated to these people he cared so deeply about. What do you see?
One thing I saw in a new way as I read this over the summer was the whole idea of partnership, or teamwork. Right at the beginning of the letter Paul says to them, "You have been my partners in spreading the Good News about Christ..." (verse 5, NLT), or "I always pray with joy because of your partnership in the gospel..." (NIV).
In his greeting Paul says, "This letter is from Paul and Timothy..." They had such close teamwork that Paul includes Timothy in saying who the letter is from, acknowledging Timothy's teamwork with him. In fact, Paul does this at the start of five other letters as well: 2 Corinthians, Colossians, 1 and 2 Thessalonians, and Philemon. He calls Timothy his brother, and also his 'true son in the faith' (1 Tim. 1:2).  Paul nurtured Timothy, mentored him, and worked closely with him in sharing the gospel of Jesus. 
What about you? Who has God given you to serve Him together with, and to nurture and mentor? Are you acknowledging them, seeing their value, and investing in them? 
On the flip-side of this (very valuable) coin, we can all benefit from being mentored. Is there someone in your life you trust enough to open your heart to, and allow them to mentor you?
You can check out this week's sermon here: http://www.crbaptist.bc.ca/media/2016-09-11-something-about-joy