Wilhelm was born in the Netherlands, but dedicated 46 years of his life to activism in the Philippines. He was the Executive Director of the NGO Alay Bayan-Luson Incorporated until his murder in July 2012.
Wilhelm initially came to the Philippines as a missionary with the Calama group and eventually, with the Missionary Volunteers (MIVO) in 1970. He pursued further studies in the University of the Philippines in Quezon City, completing a Doctorate in Sociology. Wilhelm moved to the province of Aurora in 1979, living there for 23 years. The marginalized peasants, fisher folks, the Dumagets and Aetas and other indigenous people became his next of kin. He helped these people with struggles for land rights, as well as human rights issues during the Marcos regime and the Arroyo Presidency.
As their mission in Aurora developed , health and education programs were implemented by Wilhelm and his colleagues. Through these programs, the local communities themselves rose up and coordinated further people’s organizations, perpetuating the protection and promotion of human rights.
Wilhelm was instrumental in the formation of several sectoral organizations including groups for farmers, youth, women and indigenous people. His promotion of human rights attracted the ire of the Filipino military and his groups were harassed and threatened. But Wilhelm and his colleagues stood their ground and upheld their basic rights to organize and promote welfare.
Wilhelm’s leadership of Alay Bayan Incorporated (ABI) has provided support to over 100 communities affected by natural disasters and environmental degradation. Not only providing relief, ABI has also empowered people through their Community-Based Disaster Management Program.
Wilhelm was another victim of extrajudicial killings in the Philippines , another environmental and human rights campaigner who has been silenced while basic freedoms of Filipinos. At the time of his death, he was promoting the rights of peasant worker, as well as campaigning against large-scale mining and other environmental destructive activities.