He commenced his studies for the priesthood in 1853 at the convent of Saint Francis but was forced to suspend his studies in 1861 after President Tomás Cipriano de Mosquera expropriated the lands of the church in the nation.
Riaño was appointed as the parish priest for Cúcuta and was transferred as the coadjutor to Bucaramanga following the 1875 earthquake.