In 1968, Phil and Mary were approved as World Baptist Fellowship missionaries to Honduras, and helped establish La Iglesia Bautista La Gracia (Grace Baptist Church) in Tegucigalpa, the capital of Honduras. Six years later, Dr. Gagnon was asked to help maintain the IBENIL, a Bible seminary, which eventually became an accredited school via an extension of the Landmark Baptist Theology Seminary.

Throughout the years, the Seminary has graduated many students who have entered into God's service. Most recently, Dr. Gagnon was privileged to participate in the formal graduation of eleven students held in the First Independent Baptist Church of Puerto Cortes, Honduras. Five of the graduates pastor churches.

Phil was saved in March, 1964, at Grace Baptist Church in Fort Worth at the age of 22. He is a 1968 graduate of Arlington Baptist College.

Mary was saved in a revival meeting in Winnsboro, Texas in 1952 when she was ten years old. They were married in 1964 at the Grace Baptist Church in Fort Worth, which is also their sending church.

The Gagnons have two children - Wayne and Tanya.