who is this jesus person you speak of?

Agnosticism isn't a belief in anything.

You couldn't be any more wrong.

Maybe he meant that agnosticism isn't a belief in any specific set of beliefs/doctrines/what-have-you's.

Pretty much, from my understanding agnosticism is just the denial of other beliefs whereas atheism is an actual belief in no God.

Atheism is commonly described as the position that there are no deities. It can also mean the rejection of belief in the existence of deities. A broader meaning is simply the absence of belief that any deities exist

Agnosticism is the view that the truth value of certain claims—especially claims about the existence or non-existence of any deity, but also other religious and metaphysical claims—is unknown or unknowable.[1] Agnosticism can be defined in various ways, and is sometimes used to indicate doubt or a skeptical approach to questions. In some senses, agnosticism is a stance about the differences between belief and knowledge, rather than about any specific claim or belief.