Tom Sine

Tom Sine, a long term Seattle resident, passed away on July 23rd, 2026 after a long battle with dementia. He was 90. Born in Pocatello Idaho to Katherine and Thomas Sine, Tom graduated from San Mateo High in 1954, attended Cascade College in Portland and gained a Ph.D. in history with a minor in futures study from the University of Washington in 1980.

For most of his life, Tom Sine worked as a consultant in futures research and planning for both Christian and secular organizations. Together with his wife Christine, he assisted organizations to evaluate how their world, nation and communities were changing so they could adapt more adequately to face the challenges of the 21st Century. Tom also helped Christian organizations develop a holistic theology of mission. He spoke widely at colleges, churches, and missions conferences around the world and led creativity seminars for a variety of Christian groups. 

Tom worked as an adjunct professor for Fuller Theological Seminary in Seattle for many years, teaching a course on Christian World View. He also spent several years working with World Concern on a project in Haiti, and assisted them in developing a theology of mission. He was a prolific writer. His first book The Mustard Seed Conspiracy (Word 1980) was a best seller and challenged people around the world to become more authentic followers of Jesus. His last book was 2020s Foresight: Three Vital Practices for Thriving in a Decade of Accelerating Change (Fortress Press 2020) which he co-authored with Dwight Friesen. Other books included Live Like You Give A Damn: Join The Change-making Revolution (Wipff and Stock 2016), The New Conspirators: Creating the Future One Mustard Seed At A Time, Mustard Seed vs McWorld: Reinventing Life and Faith for the Future (Baker 1999), Cease Fire: Searching for Sanity in America’s Culture Wars (Eerdmans 1995), Live It Up! How To Create A Life You Can Love (Herald Press 1993). He also co-authored with his wife, Dr. Christine Sine, Living On Purpose: Finding God’s Best for Your Life published in January 2002. 

Tom and Christine are the founders of Mustard Seed Associates. They focused on raising awareness of issues facing Christians and churches in the future and enabled people to develop creative responses. Tom purchased 40 acres on Camano Island in 1989 as a retreat site. He was passionate about seeing this property develop as a site where young people could learn more about a whole life faith. Together with Christine he facilitated Celtic retreats on the land each year. The property was renamed Circlewood in 2017 when James Amadon and Forrest Inslee took over leadership. Tom was delighted to see the first building, the Sine Center for Ecological Learning, completed at Circlewood last year.

Tom lived together with Christine, his wife of 34 years, in a small intentional community in Seattle called The Mustard Seed House. They loved doing hospitality and often entertained both friends and strangers in their home. They also loved to travel together and enjoyed many adventures in North America, Australia, New Zealand, Britain, Europe and Asia. Tom enjoyed sketching, was known for his wonderful BBQ sauce and found great joy in their golden retrievers Bonnie and Goldie. He was well known for his ability to get lost anywhere in the world.

Tom was predeceased by his sons Thomas Wesley Sine and Clinton Stuart Sine and survived by his wife Christine Aroney-Sine.

A memorial service will be held on August 26th at 2:00 pm at Bethany Presbyterian Church, Queen Ann Hill in Seattle. It will be live streamed here: https://bpcseattle.online.church/. In lieu of flowers please make memorial donations to Circlewood https://www.circlewood.online/ to help enable the further development of the land Tom was so passionate about.