[Sidenote:  Religion of Mohammed described.] This Islam, so called from its demanding the entire “surrender” of the believer to the will and service of God, is based on the recognition of Mohammed as a prophet foretold in the Jewish and Christian Scriptures—­the last and greatest of the prophets.  On him descended the Koran from time to time, an immediate revelation from the Almighty.  Idolatry and polytheism are with iconoclastic zeal denounced as sins of the deepest dye; while the unity of the Deity is proclaimed as the grand and cardinal doctrine of the faith.  Divine providence pervades the minutest concerns of life, and predestination is taught in its most naked form.  Yet prayer is enjoined as both meritorious and effective; and at five stated times every day must it be specially performed.  The duties generally of the moral law are enforced, though an evil laxity is given in the matter of polygamy and divorce.  Tithes are demanded as alms for the poor.  A fast during the month of Ramzan must be kept throughout the whole of every day; and the yearly pilgrimage to Mecca—­an ancient institution, the rites of which were now divested of their heathenish accompaniments—­maintained.  The existence of angels and devils is taught, and heaven and hell are depicted in material colors—­the one of sensuous pleasure, the other of bodily torment.  Finally, the resurrection, judgment, and retribution of good and evil are set forth in great detail.  Such was the creed—­“There is no god but the Lord, and Mohammed is his prophet”—­to which Arabia now became obedient.

[Sidenote:  Arabia apostatizes; but is speedily reconquered and reclaimed, A.D. 633.] But immediately on the death of Mohammed the entire peninsula relapsed into apostasy.  Medina and Mecca remained faithful; but every-where else the land seethed with rebellion.  Some tribes joined the “false prophets,” of whom four had arisen in different parts of Arabia; some relapsed into their ancient heathenism; while others proposed a compromise—­they would observe the stated times of prayer, but would be excused the tithe.  Every-where was rampant anarchy.  The apostate tribes attacked Medina, but were repulsed by the brave old Caliph Abu Bekr, who refused to abate one jot or tittle, as the successor of Mohammed, of the obligations of Islam.  Eleven columns were sent forth under as many leaders, trained in the warlike school of Mohammed.  These fought their way, step by step, successfully; and thus, mainly through the wisdom and firmness of Abu Bekr and the valor and genius of Khalid, “the Sword of God,” the Arab tribes, one by one, were overcome and forced back into their allegiance and the profession of Islam.  The reconquest of Arabia and re-imposition of Mohammedanism as the national faith, which it took a whole year to accomplish, is thus described by an Arabian author, who wrote at the close of the second century of the Mohammedan era: