The Collaborative International Dictionary of English v.0.48:

Churchgoer \Church"go`er\, n.
   One who attends church.
   [1913 Webster]

WordNet (r) 3.0 (2006):

churchgoer
    n 1: a religious person who goes to church regularly [syn:
         churchgoer, church member]

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "churchgoer":
   Christian, God-fearing man, accepter, adorer, assembly, beadsman,
   believer, brethren, catechumen, celebrant, chapelgoer, churchgoers,
   churchite, churchman, class, communicant, congregation, convert,
   daily communicant, devotee, devotionalist, disciple, evangelist,
   fanatic, flock, fold, follower, good Christian, idolater, laity,
   laymen, minyan, neophyte, nonclerics, nonordained persons, parish,
   parishioners, people, petitioner, pietist, prayer, proselyte,
   receiver, religionist, revivalist, saint, seculars, sheep, society,
   suppliant, supplicant, supplicator, theist, truster, venerator,
   votary, worshiper, zealot