What do you think first hearing this expression “New Age”? For me this word is strongly linked with another expression:
“The Age Of Aquarius”, you know, hippies, hashis and happiness ... I recall this “Hair” musical.
It was a big hit In the early 70s, the babyboomer generation were in their twenties and intended to change almost everything. Because in their eyes all generations before had failed, wars, injustice, pollution etc. rooted in false priorities and doctrines.

But then, in the early 1960 years began a movement which faszinated almost every teenager in the world.
Rebellion against “the establishment”, against “suppression”, against war (in Vietnam) and against adult rules. This kind of revolution was mainly expressed through a new kind of music, drug abuse, long hair (of course), and rude behaviour.

What are the believes and the differences to christian doctrines?
Here is a chart to define it:
 

The disciples and followers of the New Age Movement claim that there is one goal but many ways to achieve it.
But Jesus said: “I am the way and the truth and the life. No one comes to the Father except through me.” (John 14:6).

There will be a One-World-Government, a One-World-Economy, and a One-World-Religion. Satan and his human followers will deceive many but those who are forewarned will realise the lie.