Sea Breeze, thanks for your followup post. I believe, as stated by a number of atheistic scientists, that there is cosmic purpose for us and that no god gave us a purpose.
Our purpose is subjective in the same sense that our preferences for certain flavors or certain colors is subjective. Regarding what is someone's purpose involves murder, it like the way our USA constitution says we have certain freedoms. The Supreme Court has ruled that the extent of some of those freedoms is limited by whether or not the acting of them by a person hinders the same freedoms of others (for example how one practices their religion or there philosophy). Humans are social beings and we are all dependent (though to varying degrees) upon other humans, unless someone is like a feral child living in the wild with no human language. As a result, especially if we live in cities, we need to get along (at least to some extent) with other humans, and thus murder is not acceptable (at least not me and most other people). There are thus natural limits on what kind of purposes people can get away with giving to themselves and carrying out.
To say that "atheists do in fact beleive[sic] that we are just chemicals and copying mistakes" in quite accurate. We are a collection of chemicals in which many of the chemicals are highly animated and grouped in such a manner that their grouping consists of living cells. Likewise the living cells in the brains are grouped in such a way that mind is produced and exists. Likewise working human made electronic computers make decisions, and such is possible because of the way the components of the computer are structured and organized, because of the data inputs to the computer, and because of the electrical power in the operating computer.
Sea Breeze, my post on page 5 of this topic thread did not was specifically "highlighting moral subjectivity as a great tenet of atheism". My comment about a great tenet of atheism was about freedom to choose one's purpose - not about morality being subjective. In this topic thread I have avoided the topic of whether morality is subjective or not, except to the extent of what I mention above in this post.