Paul wanted the two women that he addressed by name to come to an agreement by entreating each to embrace the mind of Christ. Understanding human nature, he calls for “a true companion” to assist with settling the 
dispute between them and restoring the peace in the church at Philippi. Philippians 4:3 says, “Yes, I ask you also, true companion, help these women, who have labored side by side with me in the gospel together with Clement and the rest of my fellow workers, whose names are in the book of life.”
Paul has already focused some attention on the need for unity in the church at Philippi. He knows how crucial it is to the health and growth of the body and the individual members of the body. When unity goes the calling and purpose of the individual parts as well as the whole is unhealthy and cannot function as God intends. Thus Paul calls on help from others to work out the difficulties between the two parties. We don’t know who the “true companion” that Paul addresses is. There are numerous suggestions, but regardless of your view we cannot miss the main point that Paul wants the two who are at odds with each other to resolve their differences and get back on the same page.
As members of a family we live in homes with others. As members of a society or neighborhood we share community services and utilities with others. As members of the Body of Christ we live with others and share wonderful spiritual truths with each other. Although we see much dissent and confusion around us we are to live differently in the church. As believers we must love side by side. We must learn side by side and we must live side by side. We are all saved by grace through faith. The ground before the cross is perfectly level on which we all stand. No one is better than anyone else. No group or individual can claim to better than anyone else. But pride in our personal opinions and preferences always undermine the purpose and work of the church and destroy the joy God intended. In the next verse Paul exhorts us to “rejoice in the Lord always.” We won’t have much true joy peace, harmony and unity in our homes or churches.