The simplicity of the Sanctuary, Chapel, and church in general is a result of our iconoclastic Protestant heritage. Iconoclasm is the intense opposition to icons or anything that might vaguely resemble an idol.
When Puritans left England in the early 1600s, it was in part because they gave up on getting the Church of England to be less what they considered Roman Catholic. They worried that the fancy crosses/crucifixes, the statues of saints, and pictures of Jesus, etc., were tempting Christians to worship things rather than God.
This perspective probably wasn't as intense after a while, but when most Congregational churches rebuilt their Meetinghouses in the 19th century, not only did they recommit to simplicity but it also was the trend to paint the churches white and have clear glass windows, which added to the simplicity feel. The exterior of the second Meetinghouse (from the 18th century) was likely painted a bright color, for instance.
Narthex - The lobby area where most worshipers first walk inside on Sunday mornings and are welcomed by friendly greeters.
Sanctuary - The main worship space. Usually worshipers are welcomed into this space by ushers and offered a worship bulletin. Our Sanctuary (and the entire building that it's a part of) is sometimes called the Meetinghouse. This is because Congregational churches were often where the town or city had its meetings. Technically, the current space (3rd Meetinghouse, 1823-4) was built after Connecticut separated church and state (around 1819) so it may have never functioned as a Meetinghouse. Our Sanctuary seats up to 500 people.
Sanctuary Cross - By the end of 1962, after the organ and its pipes were moved from the chancel on one end of the Sacntuary to the balcony on the other end, there was a blank space above the pulpit. So the church leaders decided that even with their iconoclastic roots, they could experiment with having a cross up there. The second cross that was tried out was built by the late Jim Merrill at his construction business, with the help of a Catholic and a Jewish co-worker. It was well received and has hung above the pulpit ever since.
Chapel - The smaller worship space located in the Plymouth Building (18 West Main St.), which was built in 1951 and seat ~60 people. The Chapel is used for our early (8 AM) services and many of our healing services throughout the year.
Chancel - The area where the communion table, lectern and deacon's benches are located. Technically, the pulpit/apse area is part of the chancel. Our chancel has smooth hardwood flooring, which is a little slippery at times, especially for brides and grooms about to share vows.
Pulpit (Apse) - The space under the semicircular ceiling is formally an apse, but because it includes the pulpit—the podium from which pastors tend to preach—we often call the whole space the pulpit.
Pews - The seats in the main part of the Sanctuary. Pews are a second millennium development—in the first 1,200 years or so, generally everybody stood during worship—often separated by gender, in part because services usually weren't too long (probably under 40 minutes). Pews became especially popular in Protestant churches after the Reformation, when worship was extended to up to 3 hours on Sunday mornings, with a second helping in the afternoon. Pews became an important part of the budgetary practice in New England in the 19th century, when a local tax going to the Congregational church was eliminated, and churches began to "rent" pews each year. The closer to the front of the Sanctuary, the more expensive the pew rental. No wonder people still prefer sitting in the back of the church—it used to be less expensive!  But in seriousness, the numbers on the aisle end of the pews were the numbers used to identify your rented pew. Then in around the turn of the 20th century, pledge campaigns mostly replaced pew rentals.
Communion Table - The table usually located on the chancel and used during communion. We don't call it an altar in part because of the theological idea that the only perfect sacrifice was of Jesus on the cross and that in some people's minds the sacrament of Holy Communion is a remembrance instead of the spiritual or real presence of Christ.
Baptismal Font - The furniture that houses the baptism bowl, used to hold water for baptisms. The font gets its name from "fountain," but our font is a marble stand that hangs out on the river side of the church to the side of the chancel.
What else might you want to know about worship and the worship spaces?