I disagree that agnostics are part of the atheist spectrum.

Like religions people, atheists believe in something via an act of faith.

Agnostics dont. They are in the exact middle of the wheel of all beliefs (religions and atheists) saying... 'I don't know.'

To be an Atheist, requires faith and commitment of belief to something that can never be proven. Sure, its a belief that 'no, there are no gods'. But belief nonetheless. After all, you cannot prove there is no god, when a god could simply have forgotten earth exists, and never notices.

Thus, atheism has more in common with religion than it does agnosticism.