The religious domain has been identified as an important domain for language maintenance (Fishman 1972; Gal 1979). However, the effect of religion in language maintenance is not always positive (Spolsky 2003). This paper attempts to explore whether religion, Catholicism for this study, plays a significant role in the maintenance of Hakka in a Malaysian Chinese community. The sociolinguistic setting is Balik Pulau, which is a Hakka settlement on the Penang Island. Two sets of data are utilized for analysis: interview data with the priest, senior church members and ten Catholic families and data from participant observation. The findings indicate that the Hakka dialect is undergoing decline in Catholic families as well as at the church. This finding implies that religion has not played a significant role in the maintenance of the Hakka dialect in Balik Pulau. Instead, the Church shifted to Mandarin for mass and other religious activities, which resulted from the following factors: the religious language ideology, language-identity ideology, educational influence and linguistic ecology in the society.