INESIN originated out of the concern of men and women such as Bishop Samuel Ruiz and pastors of the United Church of Christ (USA) who were deeply committed to and concerned for the people of Chiapas. Following the arrival of many Guatemalan refugees in the 1980s and the Zapatista uprising in 1994, these people began to contemplate what they could do from a pastoral and ecumenical perspective to advance reconciliation among Chiapanecan people.

In this context, the Escuela Bíblica de Formación Integral (Bible School of Holistic Formation) opened in 1996. From the time of its formation, the institution has focused on promoting respect of differences, tolerance, and healthy relationships between different religious groups, all as an effort to help end religiously motivated hostility. From its formation, we have offered workshops addressing topics such as health, popular education and the Bible. A mix of Catholic and Protestant priests, pastors and laity have participated in these workshops and continue to share positive experiences of ecumenism with their communities.

In 2002, the Escuela Bíblical de Formación Integral became legally recognized as a nonprofit organization under the name Instituto de Estudios e Investigación Intercultural (Institute for Intercultural Studies and Research).

Throughout its history, the Escuela Bíblical de Formación Integral, now INESIN, has counted upon international support and solidarity, with both salaried and volunteer staff from a variety of nationalities and religious creeds.

Despite differences, all staff members share the same goal: to contribute to peace-building in Chiapas from an intercultural and interreligious perspective. Currently, INESIN is present in 33 municipalities and close to 4,000 people participate in its work each year.