A church's floor plan is, among other things, an argument about what worship is for, and denominations that weight word and sacrament differently build differently. Catholic and Orthodox churches place the altar, where the Eucharist is consecrated, at the architectural and visual climax of the building, often raised, richly decorated and, in Orthodox practice, screened by an iconostasis that the priest passes through rather than stands openly before.
Many Reformation traditions instead centered the pulpit, sometimes moving it to the middle of the building so that preaching, not sacrament, commands the architecture, a change that could shrink the altar to a plain communion table used only occasionally. A baptistery or font near the entrance marks baptism as the rite of admission into the congregation, encountered before a worshipper reaches the nave proper. Seating itself carries theological weight: fixed pews facing a distant altar suit a service watched more than joined, while seating gathered close around a central table suits traditions that emphasize shared participation. None of these choices is merely aesthetic. A visitor reading a church's plan, altar position, screen or absence of one, pulpit placement, is reading a summary of what that community believes happens, and to whom, when it gathers.