• Rev. Leslie Takahashi

    Senior Minister

    Leslie Takahashi serves as Minister at the Mt. Diablo Unitarian Universalist Church in Walnut Creek, CA. Prior to entering the ministry, she worked professionally in the area of leadership development, sustainable economic development and education policy and was the Assistant Vice President for Policy for the North Carolina Community College System. She is the co-author, with Chip Roush and Leon Spencer, of The Arc of The Universe is Long: Anti-racism and the Unitarian Universalist Association (Skinner House 2008)and a contributor to a number of professional publications and meditation collections. Finding Unitarian Universalism in her twenties, she has served extensively at the congregational, District and national levels both within the Unitarian Universalist Association and the UU Ministers Association. Her children, Garner and Liam, offer on-going inspiration. Send email to

  • Rev. Ranwa Hammamy

    Summer Minister

    Summer Minister – part time Ranwa earned her Master of Divinity degree at Union Theological Seminary, where she focused on Interreligious Engagement. She serves on the Steering Committee for DRUUMM (Diverse & Revolutionary Unitarian Universalist Multicultural Ministries), and was a facilitator at the UUA’s Multicultural Leadership School for youth and young adults of color. During seminary, Ranwa served as a Lead teacher with the children’s religious education program at the First Unitarian Church of Philadelphia, where she created a story-based interfaith curriculum called “Patchwork.” A self-described “UU-Muslim,” Ranwa hopes to serve both living traditions in her ministry. She is also a classically-trained vocalist, cat parent, and lover of children’s books. Send email to

Religious Education & Programs

  • Mr. Barb Greve

    Developmental Director of Lifespan Religious Education

    Mr. Barb Greve serves as Developmental Director of Lifespan Religious Education at the Mt. Diablo Unitarian Universalist Church in Walnut Creek, CA. Barb earned his Master of Divinity dgree at Starr King School for the Ministry and is a UUA Master level Credentialed Religious Educator. Barb has served as interim director of religious education to congregations in Atlanta, GA, Newton, MA and Hamden, CT. Prior to seminary he served in the UUA Office of Bisexual, Gay, Lesbian, and Transgender Concerns. Barb is the co-founder of Transgender Religious professional Unitarian Universalists Together (TRUUsT) and a tri-founder of the Guild of Interim Religious Educators (GIRE). Additionally, he is a trained Our Whole Lives (OWL) facilitator. Barb is a lifelong Unitarian Universalist and the child of a Director of Religious Education, a lapsed classical bassist, former home brewer, and a lover of Legos. Send email to

  • Marena McGregor

    RE Assistant/ Childcare Coordinator

    Marena earned her Bachelor of Arts in musical theatre with a minor in music from California State University East Bay. She has been an active participant and employee in the RE program for over a decade. Marena has worked as a caregiver, RE teacher, Children’s Choir director and even served on the Board of Trustees for two years. When not working at MDUUC, Marena teaches music and theater to children of all ages. Send email


  • Mark Tuning

    Music Director

    Mark Tuning joined MDUUC as Music Director in September 2003. He holds degrees in Music Education and Choral Conducting from George Fox University (B.A.) and the University of Oregon (M. Mus.). In addition to serving for several years as Music Director for churches in Idaho, Oregon, Illinois and New Mexico, Mark also directed Jazz Choirs in several of those locations. Mark is also Music Director for Diablo Choral Artists, a community chorus based in Walnut Creek.  He is a frequent soloist as tenor or countertenor and especially enjoys the creative opportunities of music ministry in a liberal congregation.  Send email to

  • Brett Carson


    Currently working toward his MA in Music Composition at Mills College in Oakland, Brett has performed and has had works performed around the country. Drawing from jazz, experimental, and concert music traditions, he seeks to incorporate an eclectic range of influences in his work. He currently performs and composes in two Oakland-based avant-garde groups, the Medium-Sized Band and Quattuor Elephantis.


  • Marie Arce

    Church Administrator

    Marie lives in Pittsburg with her husband and their two young daughters. She joined us for an Administrative Office position where she could utilize her ability and skills in multi-tasking, streamlining procedures, bookkeeping, and dealing extensively with the public.  Send email to

  • Tristan Thielman

    Facilities Coordinator

    I grew up in Walnut Creek CA, where my family and I joined the MDUUC community in the early 2000s. I also have over 4 years of custodial maintenance and landscaping experience with a little bit of a tech background thrown in the mix. i have worked a plethora of odd jobs over the years including sales, customer service, and working in the food industry. When I’m not at MDUUC I am usually out hiking in the shell ridge open space or composing music with friends. If you need to get a hold of me you can email me

  • Joel Koosed

    Publications Coordinator

    Joel is a semi-retired entrepreneur who spent his vocational life creating communities around shared housing, dance, and relationships between single men and women of all stripes and combinations. He has a background in psychology, publishing, and graphic arts, and a passion for interior design. A songwriter, musician, and photographer, in his spare time he likes to garden, play the saxophone, and hang out with his two Boston Terriers. Send email to