We know something of the history of the spread of Christianity, but much passed from recorded memory and much was transmitted by tradition whose accuracy has been repeatedly questioned.
Christianity emerged from the religion of Israel. Or rather, it has as its background a persistent strain in that religion. To that strain Christians have looked back, and rightly, as the preparation in history for their faith.
We must, however, note that what are usually called the high religions made their appearance within about twenty-five hundred years - most of them within fifteen hundred years.
The history of Christianity, therefore, must be of concern to all who are interested in the record of man and particularly to all who seek to understand the contemporary human scene.
