Well it's not true at all.
Christianity was not created by the Romans, it was just adopted by them.
It is and was used as a tool for oppression but in most western societies and especially Norway using the word 'handcuffs' is a bit of an overstatement.
He doesn't see Christianity as a religion. Then he has a weird definition of 'religion'. A definition most people in the world don't share.
His views are just naive in my opinion. The rulers of some societies use religion to oppress their people, but that doesn't mean that without religion everything would be fine. From what I can gather from his wikipedia article he just substituted a belief in religion with a view of his racial identity and nationalism. In my view that is a spiritual plague, a mass psychosis, aids of the spirit much more serious.