The diocese filed the civil action in Hampden Superior Court this week against several parishioners holding the vigil since June at Mater Dolorosa church.
The diocese says the steeple is unsafe and cannot be repaired while people are inside the church.
The vigil group says a structural engineer it hired found the repairs needed are relatively minor.
Victor Anop, a vigil leader, said Saturday the group will "vigorously defend our position in court."
Diocese spokesman Mark Dupont said it took the action "very reluctantly" after several attempts to explain its concerns.
The vigil group is appealing a Vatican decision last month that upheld the church’s closing.