Alexander McKenzie was born at New Bedford, Mass., in 1830, and graduated from Harvard in 1859. Since 1867 he has been pastor of the First Congregational Church, Cambridge, Mass. His voice is rich, full and sympathetic, and his pulpit style that of one man talking earnestly and directly to another, there being no attempt at oratorical effect. He is to-day probably the most acceptable preacher at Harvard, and the leading Congregational minister in New England. The discourse reprinted here is from his volume “A Door Opened,” and has been noted as one of the greatest sermons of the century.