US BASED STAFF
John Miller
Founder & Executive Director
Email: jmiller@onevisionintl.org
John founded our organization in 2005, after seeing the need for more people to serve in international settings. He aims to show who we are as believers in Christ, to all we connect with. We have the opportunity to impact lives for the better, and introduce the peace that so many are searching for. John's current focus is organizing and establishing our efforts in the Middle East.
Leon Willis
Chief Operating Officer
Email: leon@onevisionintl.org
Leon joined our staff in 2025 after 41 years of leadership in the nonprofit sector. He has a heart for bringing the Gospel to groups of people and their communities. He also enjoys growing the capacity of an organization and will help OVI to broaden our reach and impact here at home through donor relations, staff and board development, and various other daily operations. Leon is a native Knoxvilian and a member of Cedar Springs Presbyterian Church.
Rachel Cox
Dominican Republic & Brazil Director
Email: rcox@onevisionintl.org
Rachel has a tremendous heart for others and coordinates our efforts in Brazil and the DR. She enjoys working behind the scenes and building relationships with others in order to share God's love. She married her husband Jeremy in 2012 and they are both active members of the Church at Sterchi Hills in Powell, TN. She is inspired by watching the Holy Spirit work in the lives of others and is committed to sharing that joy and hope with others around the world.
Larissa Nipper
Local Logistics Coordinator
Email: larissa@onevisionintl.org
Larissa joined the OVI staff in October, 2021. After growing up in Piaui, Brazil (the same state that we work in!), she moved to the US in 2016 and lives in Knoxville with her husband Alex. Larissa oversees all of our finances and also helps plan fundraising events. It really is a small world and we are so thankful that God brought her into this team!
INTERNATIONAL STAFF
Claudia McKenzie
Dominican Republic Director
Claudia has been serving with One Vision for over four years. She is the hands and feet of our mission in the Dominican Republic. She hosts teams and reports on the day-to-day needs of their area. Through her humble work, she has helped establish our child sponsorship program, various bible studies, community outreach activities and is an ambassador for her country when our teams visit. Her bi-lingual talent makes her an excellent translator for trip participants. Hope, hospitality and deep caring spirits make her invaluable to our team.
Denise Soares
Brazil Child Sponsorship Coordinator
Denise began serving with One Vision in 2017. She directs a children's program in Rancharia, Brazil called Projeto Semear (The Seed Project). One Vision partnered with Denise to create our child sponsorship program in Brazil. Each day she teaches, mentors, and advocates for 25 children that attend the program. She also creates child profiles and takes updated photos to keep child sponsors up-to-date on their sponsor children. Her heart is to see God transform this community through the Holy Spirit working in these children and their families.
Wislaine Miller
Middle East Co-Director
After serving for the past 10 years in Brazil, South Africa, and Jordan, Wislaine now serves full-time alongside John in the Middle East. Her focus is on women's issues in-country, and managing our Brazilian relations for the Middle East work. Wis has a special desire to see children thrive no matter what their surroundings are.
Florencio & Rejane Carvalho
Brazil Trip Coordinators
Our work in Brazil would not be possible without the partnership of Florencio and Rejane. They created a NGO in Brazil called Graca&Paz (Grace & Peace) to help support local church plants and the spread of the Gospel in Piaui, Brazil. Together they coordinate all of the logistics for our trips and advise us on areas of need.
2025 Board of Directors
The board of directors are personally invested in the work of One Vision. The board exists to maintain accountability within the organization and to ensure the needs of people are met whatever the cost, even when these needs may be inconvenient and expensive. Before asking individuals and corporations to give, the board personally commits to giving through finances, time, and participation.
Hollie Miller
Lee Ficken
Bryan Balentine
Michelle Curley
David McClanahan
Jonathan Locy
Steven Montgomery
Bob Bostick