The Reformation conquered the village in 1552. In that year Chesereu/Érkeserű had 44 houses with about 300 people. In 1560 the whole village is of Reformed (Calvinist) confession. In 1587 the Reformed already have an organized church.

In 1580 the Hungarian Reformed bishop, John DAYKA of Keserű (Keserűi Dajka János) was born in Chesereu/Érkeserű, being bishop of Transylvania between 1618-1633.

The first known pastor of the Reformed congregation was named in 1600. The church school was founded in 1587, its frist known teacher is appointed in 1772. The register of births-baptisms, marriges and deaths is dated since 1765. Unfortunatelly, registers, minutes and records before 1860 were taken to national archives during the Communist era.

In 1800 the thousand member congregation decides to extend the ancient church building.

Many pastors in the 18-19th century were 30-40 years on service.

The agrarian, educational and religious Romanian "reforms" in 1948-49 nationalized the church school and many lands of the congregation. Registers between 1852-1911 must have been handed over to the local authorities. Pastor Ferenc KISS was even arrested by the secret police for weeks.

The latest renovation of the church building took place in 1981. In 1995 the once school building given back by state authorities, and the congregation decides to use it as a place for meetings and bible studies. In 1999 the very damaged roof was completely changed.

Since the 1970ies the number of church members drasticly decreased. There are still many injuries and conflicts in the congregation caused by the Communist era. In these socially and economically difficult times all we can say are the words of the Psalmist: "God is our refuge and strength" - "Gott is unser Zuflucht und Stärke" (Ps 46:2)