What are the essentials of faith?

I am a big fan of the saying "In the essentials, UNITY, in the non-essentials, LIBERTY, in all things, CHARITY."  But what are the essentials of the faith that we must agree upon or admit that we can not call ourselves Christians?  Steve Cowan has suggested the following seven items.  I have a couple of comments:

• Belief in these all of these items is NOT required for salvation
• I'm not sure I agree that belief in Original Sin is essential, but I do believe in it, and could be convinced that he is correct.

1. The Deity and Humanity of Christ
2. The Trinity
3. Original Sin
4. The Substitutionary Atonement
5. The Resurrection of Jesus
6. Justification by Faith Alone
7. The Second Advent of Christ