In the church of Philippi, there were envy, rivalry and selfish ambition. Apostle Paul was writing to them to stand firm in one spirit and have one mindset of Jesus Christ. To become one mind, there's one thing needed. It is humility. Based on verses 3-4, humility is placing ourselves lower than where we are supposed to be, and sacrificing our interests to seek others'. How can one have this humility?
Apostle Paul brings the story of Jesus, his life and death. We can find three things through which Jesus grows humility. First is his identity. He knew who he was and what to do through the fellowship and communication with God. By having a clear identity, Jesus was able to humble. Second, he lived with other people as a man, by experiencing all kinds of human relationship for 30 years. Through this, he was able to bear the fruit of humility. Lastly, he was obedient. Obedience is a characteristic of a humble person, but at the same time obedience produces humility as well.
In order to have humble mindset of Jesus, we should know who we are from the view of God, live with others in a community, and be obedient to the authorities around us.