Fr Casicas was born in 1967 in Duero, in the Philippine province of Bohol, located in the Central Visayas region.
He undertook philosophical studies for the priesthood at Our Lady of Perpetual Help Seminary at Koronadal in the province of South Cotabato. His theological training was completed at St Francis Xavier Regional Seminary in Davao. He was ordained for the priesthood for the Diocese of Marbel in 1994.
Bishop-elect Casicas completed a Licentiate in Dogmatic Theology in 2003 at the Pontifical Gregorian University in Rome.
Pastoral assignments include Chancellor (1994-1995), Dean of studies at Our Lady of Perpetual Help Seminary (1995-2000), Chaplain of the Philippino community in Rome (2001-2004), Professor of Philosophy at the University of Notre Dame of Marbel in Koronadal (2005-2006), Parocchial Vicar of Jesus the Good Shepherd parish in Polomolok (2006-2009).
The Bishop-elect spent a sabbatical year at Our Lady of the Philippines Trappist Monastery in Guimaras. After this experience, he was the Parocchial Vicar for three parishes at General Santos City. From 2013 to the present he has been Director of a Professor at St John Vianney Seminary of Camaman-an in Cagayan de Oro City.