Born in Lille (France) in 1971, Gabriel graduated as an agricultural engineer in 1994. After two years volunteering (civil service) in a Nature Park (Vercors) he joined the Society of Jesus in 1996 and followed the regular French Jesuit path of formation: noviciate in Lyon; philosophy and theology in Paris and a two-year regency in Icam (School of Engineering) – Nantes. After his diaconal ordination (2006), he was appointed to Lille as coordinator of internal engineering courses in Icam-Lille. He was ordained priest in Lille in 2007.