This verse serves as a basis for the poetic description of how Christ was born, lived and died. The "mind" that Paul refers to is the focus of Christ's life, which is humility. It is clear to Paul that this is something that the Philippian believers possess, or at least have access to, as Christians. As a believer, we should adopt an attitude similar to that of Christ. 
Paul believed that the most effective cure for a lack of peace and joy is a mind focused on Christ. In other words, it is a mind that is submissive to the guidance and leading of the Holy Spirit. This is a humble attitude that seeks to accord greater importance to others than to oneself. The Lord Jesus Christ calls upon us to be united in mind, love one another, and live in harmony with a singular focus.
Indeed, the joy of the Lord is our strength, and we are encouraged to rejoice forever, pray without ceasing, and live in godly unity with one another. However, we can only accomplish this if we allow the Word of Christ to dwell in us abundantly and allow the Mind of Christ to guide our actions, attitudes, and motivations. Let us reflect a spirit of humility in which we regard the needs of others as more important than our own.

Dear Heavenly Father, it is an amazing truth to realize that I am a new creation in Christ and that God's Holy Spirit lives within me. May I live a life of complete dependence on You and in godly unity with my Christian brothers and sisters? Please keep me from contentions and strife and assist me in putting others' needs before my own. In all my days, I pray that the mind that was in Christ Jesus will dwell in me fully so that I may act justly, love mercy, and walk humbly before You now and in the future. 
In Jesus's name I pray. Amen.