He attended St. Louis Preparatory Seminary South, Cardinal Glennon College and Kenrick Seminary and St. Louis University Divinity School. He was ordained by Cardinal John J. Carberry in 1970 at the Cathedral Basilica of St. Louis.

Following ordination, Father Kester was appointed associate pastor of St. Thomas More Parish in Bel-Ridge. He was named associate pastor of Visitation-Holy Ghost Parish in St. Louis in 1974, St. Lucy Parish in Jennings in 1976, Immaculate Conception Parish in Union later that year, Little Flower Parish in Richmond Heights in 1979, St. Peter Parish in Kirkwood in 1981 and St. George Parish in Affton in 1985.

Father Kester was named pastor of St. Adalbert Parish in St. Louis in 1987 and Our Lady of Perpetual Help and Most Holy Name Parishes in St. Louis in 1990. He was named senior priest in service at Immacolata Parish in Richmond Heights in 1993 and administrator of St. Matthias Parish in Lemay later that year, then pastor there in 1994. Father Kester was appointed senior associate pastor of St. Ambrose Parish in 2007, and he retired to reside at St. John Bosco Parish in 2010.

There will be a private service for the immediate family subject to the restrictions imposed as a result of the COVID-19 guidelines.