In 1863, Fiske entered the ministry for the Methodist Episcopal Church, served as pastor of the Methodist Episcopal in Jackson, 1863–66; of the Central Methodist Episcopal Church in Detroit, 1866–69; and of the First Methodist Church in Ann Arbor, 1869–72. In 1872 he was the Presiding Elder of the Ann Arbor District. In 1873, he was awarded the D.D.
In 1863, Fiske entered the Methodist Episcopal Church ministry and served as pastor at various churches: Jackson from 1863 to 1866; Detroit from 1866 to 1869; and Ann Arbor from 1869 to 1872. In 1872, he was the Presiding Elder for the Ann Arbor District. In 1873, he received a Doctor of Divinity degree.