Steve Ko

Stephen serves as Missions Pastor at Aletheia Church, where he is passionate about equipping and sending God’s people to boldly share the good news of Jesus—across the street and around the world. He loves helping congregants see their everyday lives as opportunities for evangelism, while also inviting them into meaningful engagement with God’s global mission.

An author, pastor, and physician, Stephen’s work uniquely weaves together faith, medicine, and global health for the sake of the gospel. In addition to his role at Aletheia, he practices as a pediatrician and preventive medicine doctor within the Mass General Brigham system and leads the Lausanne Movement’s Health Network, mobilizing Christians worldwide to integrate healthcare and mission.

Over the years, Stephen has served as a Senior Pastor in the Christian and Missionary Alliance, worked as a Medical Officer with the Centers for Disease Control and Prevention, and taught Global Health at Boston University as well as Evangelism and Missions at Alliance Theological Seminary. With training in medicine, public health, and theology (MD, MA, MPH, MDiv), he brings an interdisciplinary approach to helping the Church live out the gospel in word and deed.

Stephen is the author of Faith Embodied (Zondervan) and has contributed to several other books. Through his speaking and writing—including his newsletter—he seeks to encourage and equip believers to live on mission, faithfully sharing Christ in every sphere of life.

He is also known as “KOKO the Clown & Magician,” using humor, creative gospel magic, and the medicine of laughter to joyfully share Christ with people of all ages—opening doors for evangelism in unexpected places.

Stephen lives with his wife, Bridget, who loves welcoming families, friends, and neighbors into their home. Together, they enjoy spending time with their two fun-loving sons, Topher and Luke.

Contact Steve if you’re interested in engaging in local or global missions!