In its mission statement, the First Parish Unitarian Universalist Church describes itself as a "liberal religious community" that welcomes a diverse congregation, including gay, lesbian, bisexual and transgender parishioners. The church is led by Rev. Marta Flanagan, who joined First Parish in the fall of 2009 and is often referred to simply as "Marta" by her parishioners.

Services are held every Sunday, starting at 10am and running until 11:30am, and are followed by an informal coffee and friendship hour.

First Parish offers a full religious education curriculum for students in kindergarten through grade eight. A youth group of high school youth and adult advisors meets on Sunday nights from 7pm to 8:30pm and participates in a variety of activities, including community service.