The Rev. Kassouni was ordained on January 20, 1957, by the New York City Association of Congregational Churches in the Armenian Evangelical Church of New York City, which he served as his first parish in 1959. From there he went on to serve the First Armenian Presbyterian Church of Fresno in 1964, and the United Armenian Congregational Church of Los Angeles in 1977. In Fresno he rallied the congregation to go ahead with building plans for a new church complex, successfully building two of their three complexes while with them as pastor. During his years of ministry in these churches he helped bring the Eastern and Western branches of the Armenian Evangelical communities into one Union, along with their youth organizations. He also helped in the formation of Camp AREV and the Armenian Studies Program in Fuller Seminary, Pasadena.
While Moderator of the Union in the East, he helped raise funds for the purchase of a building in Toronto for the first Armenian Evangelical Church in Canada, and presided at the ordination of their pastor, the Rev. Dr. Solomon Nigosian. He was a key participant in the planning and successful opening of the Armenian Evangelical parochial school in America, the Charlotte and Elise Merdinian Armenian Evangelical School of Sherman Oaks, CA. His vision and efforts for a new church in Hollywood for the many new immigrants arriving from Armenia culminated in the formation of the Armenian Evangelical Church of Hollywood in 1982, with the Rev. Abraham Chaparian as pastor. In the early and formative years of the Armenian Assembly of America, Rev. Kassouni was a member of the Steering Committee which later evolved to be its Board of Directors. While in New York City, he served on the Board of Directors of the Armenian Missionary Association of America, of Paramus, N.J., and more recently he served on the Board of Trustees of Christian Aid Mission, centered in Charlottesville, VA.
In 1983 Rev. Kassouni had a change in the direction of his ministry, moving on to pastor Presbyterian churches outside of the Armenian community. He served the Palmdale Presbyterian Church, Tustin Presbyterian Church, Christ Presbyterian Church, Huntington Beach, and then was called to the position of Associate Executive Presbyter, Los Ranchos Presbytery in Anaheim, with a constituency of 55 churches. In this capacity he helped organize four new churches including Laguna Niguel, Rancho Santa Margarita, Yorba Linda, and North Huntington Beach. He retired in 1996, but has continued to serve parishes ever since in the capacity of Interim Pastor. These have included First Presbyterian Church of Garden Grove, two years as Interim Executive Presbyter of San Fernando Presbytery, Geneva Presbyterian Church of Laguna Hills, Yorba Linda Presbyterian Church, and most recently, Morningside Presbyterian Church of Fullerton.
Attendees at this reception came from these many parishes and ministries, sharing their love, respect and expressions of congratulations. On this memorable occasion Rev. Kassouni was honored for fifty years of uninterrupted ministry, spanning both the East and West coasts among a score of churches, both Armenian and non-Armenian. His vision and passion is to continue serving where needed for as long as God gives him strength.