No, I believe it is not. Paul Young, author of The Shack, and many others have advocated Christian Universalism to varying degrees (see my reflections on The Shack).
Here are some resources that can help you understand the issue and what the Bible actually says. In addition to these below, here is my chapter on Hell from If God Is Good.
Responding to “Christian Universalism”
Is universalism / universal salvation biblical?
