Again, the central core idea expressed my Walter Martin is about ONLY the resurrection of Jesus Christ...that is alone and the ONLY thing he is talking about that makes us Christian.
If you don't see that fact?...better go listen again.....its there.
as for how did I find that link?....I did a GOOGLE search.
Here is the results of another GOOGLE search - http://www.godonthe.net/evidence/rom10_9.htm
This is what im pointing to as being the reason and the way we become Christian....