To quote the AskOxford entry for Humanism it is “a rationalistic system of thought attaching prime importance to human rather than divine or supernatural matters”. The key word there is rationalistic for that is a prerequisite to becoming a true atheist. 

One can not simply not believe in God to be a genuine atheist in my eyes, one must also be rational and understand why there can not be one. Being a humanist is usually the biproduct of this process, once someone critically looks at the universe you fast realise that we as human beings have fought an uphill struggle since the dawn of our species.

It’s also my humanist views the drive my arguments with theist’s concerning the purpose of life (and death). I mentioned previously I have discussed the matters of life and death with Theists of different denominations and we all arrive at the same point. The other person’s views are sad and narrow minded. 

The idea that we are born into sin owing our lives to a creature we’ve never seen is a shocking one to somebody who embraces the theory of evolution and the principle of natural selection. As you understand those processes (which tragic few do) you realise that the odds really are stacked against us (some silly billions and billions:1 count if you believe tax evaders). 

Theists will mount the probability of life “occuring” as a proof of intelligent design but humanists would use the same research to highlight that our species is even more amazing that we thought. Of course I say ‘would’ use because theist scientists are notoriously bad at submitting papers to be peer reviewed preferring ignorance panderings sites like AnswersInGenesis.

Ultimately nobody in the discussion concerning life purposes can be proven to be concretely right because theists do not engage you at the scientific level and since we lack the victory by default clause in science, nobody ever wins. 

They believe our lives are misguided and we’ll suffer eternally for it and we think they’re wasting the only life they have following shephards who tell them the clouds are watching.

The important words in that sentence are “belive” and “think”, in case you didn’t spot that.

For more information on Humanism consult the BHA’s website, they do great work.