A certain current of dualism runs through the Christian Scriptures and the teaching of the Church.

God and Satan, heaven and hell, are the only alternatives.

Every one must choose between them.
In the current theology, this dualism has been so emphasized as even to exceed that of the Zend Avesta.

The doctrine of everlasting punishment and an everlasting hell has always been the orthodox doctrine in Christianity, while the Zend Avesta probably, and the religion in its subsequent development certainly, teaches universal restoration, and the ultimate triumph of good over evil.

Nevertheless, practically, in consequence of the greater richness and fulness of Christianity, this tendency to dualism has been neutralized by its monotheism, and evil kept subordinate; while, in the Zend religion, the evil principle assumed such proportions as to make it the formidable rival of good in the mind of the worshipper.