Download a copy of “The Definition of Christianity” by John Lennox and David Gooding (no strings attached, no email required) from Myrtlefield House Publishers. They have a number of other free resources available too.
Christianity is not essentially a system of morality (as is Confucianism) that has to be adapted to the changing fashion of the centuries or else become outmoded. Nor is it a system of abstract universal philosophical truths, the validity of which is independent of the thinkers who first perceived them. Nor is it like many a pagan religion was, a system of rituals which depended for their effectiveness on being performed correctly.
In this video, scientist and mathematician Professor John Lennox deals with this question.
You can hear more from him via his website, www.johnlennox.org