GLASSITES or SANDEMANIANS, a religious sect that first appeared in Scotland about A.D. 1728, when Mr Glass, a minister of the Scottish Established Church, avowed opinions on church government approaching very nearly to those of the Congregationalists. About 1757 Robert Sandeman appeared as an advocate of the same opinions, and in 1762 he organized a congregation. The prominent distinguishing doctrine of the Glassites relates to the nature of justifying faith, which Sandeman maintained to be "no more than a simple assent to the divine testimony passively received by the understanding." Certain peculiar practices also are observed by this sect, which are by them supposed to have been prevalent among the primitive Christians, such as weekly communions, love-feasts, mutual exhortations, washing each others' feet, plurality of elders, the use of the lot, and several others.
In 1851 the number of Glassite congregations in Great Britain was twelve, with aggregate accommodation for about 2000 persons.