At the end of a year in which almost everything seemed to have been altered by the COVID-19 pandemic, churches are making adjustments for Christmas Eve and Christmas Day services that adhere to social distancing guidelines. In order to keep services from exceeding limits, churches are requiring parishioners to register ahead of time for services that will be well below normal capacity. On Dec. 8 Gov. Charlie Baker limited indoor capacity to 40% for places of worship. In addition, singing is also being discouraged. Raymond L. Delisle, chancellor and director of communications for the Roman Catholic Diocese of Worcester, said that the churches had to put the preregistration systems in place because of the popularity of Christmas Masses.