Skeptic, nice to meet you! We've not been introduced yet. I'm EV, your resident moral philosopher and musician. Would like to present to you a suggestion below.
All people are amoral if you define Morality as absolute (as in all-encompassing and having 'GOOD' and 'BAD' as universally constant entities. Morality is a Human construct, we each have an individual worldview built from the experiences of our lives. Because every culture's morals end up different, it's passed down through family and upbringing. This may or may not feature religion.
Your morals did not come directly from God, but from writings about your God in a book, and from growing up in the world around you. The debate from whether God created the book and so the morals are of Divine origin is irrelevant to this topic, which is about the morals of Atheists.
My moral worldview came from growing up and the moral and experiential imprints left on me by others. Some of that influence may have come from Christian sources, such as friends or the Chapel services I was forced to attend at School, but most didn't, and came from the principle of simply treating others as you'd like to be treated yourself. The rest you learn through time.
Think of a toddler smashing their parents stuff up. They don't know the concept of right or wrong. You can teach them it's wrong because God says so or because it's wrong as they are hurting their mothers feelings.
Either way, the morals appear, but are not necessarily from God.
We can show that since it is possible to divulge morals not from God, then to say "Atheists are Amoral" is a logical impossibility, as they could obtain morals from another source and indeed many of my good colleagues on this forum have done.