Heaven, in its theological sense, is that portion of the infinite space in which the Lord of all things, though present throughout all, is supposed to give more immediate manifestations of his glory. It is also the place, or the state or condition, of the blessed spirits, and of the souls of just men made perfect who are admitted into the participation or the contemplation of the divine beatitude. It is the special seat of the glory of the Most High, in which his angels minister to him, and the blessed spirits abide in perpetual praise and adoration. In the Scriptures the word is used in various senses: (1) for the region of the atmosphere; (2) sometimes for the region of the stars—the hosts of heaven; (3) as a state of blessedness attainable even here, as in Eph. ii. 6, where it is said 'God hath raised us up together (with Christ), and made us sit together in heavenly places;' and also in Phil. iii. 20, where the conversation of the saints while yet on earth is said to be 'in heaven;' (4) as the place where God dwells, where the angels and the spirits of the saints are congregated, whence Christ came and whither he has returned (John, xiv. 2, &c.). Many of the saints of Christendom in moments of ecstatic elevation of spirit have believed that glimpses into heaven have been vouchsafed to them, but their accounts of these visions have usually been but incongruous and contradictory. The figurative language in which its unseen glories are described in Scripture has made such an excitation of fancy the more easy for devout souls rapt in profound meditation about what it has not been given to the eye of man to see nor the heart to conceive.
Aristotle declares that all men have a conception of gods, and that all agree in placing their habitation in the most elevated region of the universe. The Egyptian, the Scandinavian, the Assyrian, and all primitive religions maintain the existence of a heaven as the place of reward after death for virtuous lives lived on earth; and indeed it may be taken as the universal corollary to the universally held belief in the immortality of the soul, even though it may be only under the form of the final stage in a cycle of purificatory transmigrations. But among primitive peoples it is little more than a dim and shadowy continuation of this present world, the pale ghosts that inhabit it wearing the form and fashion that they wore in life. The idea of future retribution enters early into the moral consciousness of man, but it would hardly be true to say that it is everywhere present. The Teutonic warrior had his war-horse and his armour laid in his barrow that he might continue into the spirit-world the joys of life, his Valhalla being but a glorified extension of the warrior's life, just as the Red Indian's paradise is but a richer and more extensive hunting-ground. Yet the unseen life is often but poor and cheerless compared with the warm and actual world—even in the Elysian fields the shade of Achilles would gladly change places with the meanest soldier in the Grecian host.
The Koran adopts the Cabbalistic notion of seven heavens, which rise above each other like the stages of a building; and it places the chief happiness of heaven in the unrestricted and inexhaustible joys of sense. The Cabbalistic writers divide these seven heavens according to the successive degrees of glory which they imply. The seventh is the abode of God and of the highest order of angels; the sixth, fifth, fourth, and third are the successive abodes of the various grades of angels, arranged according to the degrees of dignity. The second is the region of the clouds, and the first the space between the clouds and the earth.
For the development of Jewish and Christian Eschatology, and the significance of the conception of heaven, see the article HELL, under which the subject of future rewards and punishments is discussed with some fullness.