Career
After graduating from the Old Catholic seminary at Amersfoort in 1870, Gul was ordained a priest. He worked in Amsterdam (Street John and Willibrord), Zaandam (Street Mary Magdalene) and Utrecht (H James). In 1886 he became pastor in Hilversum He was consecrated Archbishop of Utrecht on 11 May 1892.
Many Old Catholics and Independent Catholics trace the lineage of their orders through him.
On 5 October 1909 he consecrated January Maria Michał Kowalski, the first Minister Generalis (Minister General) of the order of the Mariavites. On 28 April 1908, Gul consecrated Father Arnold Harris Mathew to be the first Old Catholic bishop in the United Kingdom.
Assisting Gul were Bishop Johannes Jacobus van Thiel of Haarlem, Bishop Nicholas B. P. Spit of Deventer, and Bishop J. Demmel of Bonn, Germany.