The Harvard Study of Adult Development is a decades-long project that’s resulted in a greater understanding of the importance of healthy relationships. The research began with a group of 268 sophomores at Harvard University in the 1930s and later expanded to, among others, 456 Boston inner-city residents. Researchers have conducted interviews with the participants and pored over their medical records every few years. What they’ve discovered is that close relationships are the biggest factor in predicting happiness and health. It turns out that if we surround ourselves with the right people, we’ll likely experience a deeper sense of joy.

This appears to reflect what the apostle Paul is describing in Philippians 1. Writing from prison, Paul can’t help but tell his friends that he thanks God for them every time he remembers them, praying “with joy” (v. 4). But these aren’t just any friends; these are brothers and sisters in Jesus who “share in God’s grace,” partners in the gospel with Paul (v. 7). Their relationship was one of sharing and mutuality—a true fellowship shaped by God’s love and the gospel itself.

Yes, friends are important, but fellow companions in Christ are catalysts of a true and deep joy. The grace of God can bind us together like nothing else. And even through the darkest seasons of life, the joy that comes from that bond will last.