Meet the Team

  • Virgil Tanner

    As the Senior Director of OneTree, Virgil is responsible for leading the team to help mission, marketplace, and ministry leaders thrive holistically, do beautifully integrated work, and become everything God dreamed them to be, believing this to be a primary means for stewarding the reviving life of God through His people into the world.

    Virgil holds a B.S. in Biology, an M.A. in Religion and Cross Cultural Studies, and an MEd. in Curriculum and Instruction. He is presently working on an EdD in Christian Leadership.

  • Calvin Tiessen

    Calvin is the Director of Training and part of the team preparing missionaries for fruitful field service, while also helping missionaries thrive in their places of ministry.

    Calvin holds a PhD in Cultural Anthropology and Missions. He has served for 25 years with Wycliffe Bible Translators. He also holds an M.A. in Biblical Studies, an M.A. in Linguistics, and a B.A. in Education.

    Calvin has lived most of his life on the mission field. He was born in the Philippines, where his parents served with SEND International, and then served with his wife, Gabi, in Central Asia for 18 years and Albania for 5.

  • Janice Maurizi

    Janice is the Director of Care and leads our Integrated Care Team as they walk with people into healing, thriving, and vibrancy in their lives. 

    Janice has an MA in Marriage and Family Therapy and 19 years of experience in clinical, ministry, and non-profit organizations. She brings a unique perspective, having worked both domestically in the U.S. and internationally in India, Kenya, Ukraine, Poland, South Africa, and Romania with organizations, children, and families. She is a TBRI practitioner and a Trauma Competent Caregiver Facilitator with extensive experience training and teaching about trauma and staff care and health.

  • Joy Tanner

    Joy is the Intake Coordinator for the Integrated Care Team and helps to design personalized care and training plans for clients. She is a mother of five and spent nine years as a pastor’s wife in Nashville, TN, before moving to Central Asia with her family to lead a disciple-making team in a Muslim republic. 

    Joy has 15 years of experience working and living in the Muslim world and brings an extensive background in counseling and training to the team, which she uses to provide trauma debriefing and care for clients. She also holds a B.S. in Education with concentrations in psychology and English. Her passion is to guide people on their journey to freedom through knowing and being loved by Jesus.

  • Gabi Tiessen

    Born and raised in Latin America and Michigan by American parents, Gabriela is familiar with cross-cultural life. She and her husband, Calvin, served with Wycliffe Bible Translators for over 20 years, working in the Caucasus and Albania. 

    Gabi’s primary roles have been as a Language and Culture Learning Coach and as a trainer; she has designed and facilitated courses in cultural adjustment, language learning, and intercultural dynamics. Her primary passion is to see cross-cultural workers equipped to flourish in another culture, fully rooted in the Lord, as they seek to build relationships and incarnate the love of Christ in their contexts. She holds a B.A. from Hope College and an M.A. in Intercultural Studies through Fuller Theological Seminary.

  • Ana Lucia Cornejo

    Ana is an important part of our Integrated Care Team, offering services in English and Spanish. From Peru, she can serve our international clients via virtual sessions and engage them in their current context.

    Ana has an MA in clinical psychology and worked for Kids Alive in Peru as the national coordinator of Therapeutic Intervention. She currently works for CAFO Research Center as the Liaison for Latin America. She serves as a member of the Peru por los niños committee, an alliance of organizations that advocate for every child to live in a family. She is a TBRI Practitioner and Trauma-Competent Care Facilitator.

  • Carrie Gaul

    As a speaker, author, and lay counselor, Carrie specializes in guiding women toward deeper spiritual growth and relational healing with God, with one another, and within their own story. 

    With over 30 years of experience in life-on-life ministry, Carrie is a certified trauma-care specialist adept in healing prayer and neurological integration.  Her holistic approach guides individuals toward becoming more whole-hearted and thriving in their faith journey.

    Carrie serves as a Staff Care Specialist with Life Action, a Fellow with The Truth Collective, and an adjunct staff with OneTree.

  • Del Fehsenfeld

    Del is a leader-health specialist and lead master trainer for Consentia Group. He is a Licensed Marriage and Family Therapist as well as a Neuro Change Coach with over 25 years of pastoral experience. He also leads Relational Health programming for Life Action and serves as an adjunct staff member for OneTree.