I'm a humanist and a member of the British Humanist Association (BHA). I've identified myself as a humanist since I had the term described to me when I was eighteen, I was already a humanist for some time before that, but didn't know it.
The BHA describes humanism as follows:
"Humanism is an approach to life based on humanity and reason - humanists recognise that moral values are properly founded on human nature and experience alone. Our decisions are based on the available evidence and our assessment of the outcomes of our actions, not on any dogma or sacred text.
Isn't that a wonderful way to live your life? To accept that there's no higher power judging us or telling us what to do. To accept that we must find our own way to live a good life. That morality isn't something set in stone, but something that we must endeavour to improve as we learn more.
Humanism includes atheism but introduces an ethical aspect. The Humanist Manifesto is a not a dogmatic set of principles, instead it captures the current thinking in an evolving world view. There have so far been three versions of the Humanist Manifesto, each taking into account how society has developed and what has been learnt since the previous version.
Humanism is a grown-up lifestance. Humanists accept that just as we are able to look back at those who supported slavery with a sense of moral superiority, future humanists will be able to look back at us with a sense of moral superiority. This encourages us to think about how we could improve our society, for example by eradicating homophobia. We can't just rest on our laurels and believe that if we just follow a particular set of rules then we'll have lived a good life. We have to try harder than that and evolve what it means to live a good life.
Being a humanist makes me feel alive. I know that I have only a limited lifespan and that this life is the real thing, not a rehearsal. I owe it to myself to make the most of it. For me that means achieving personal happiness and fulfilment in the context of aspiring towards a greater quality of life for everyone.
Humanism definitely helps with understanding what personal happiness and fulfilment involves. I've got no higher power to thank or blame for events in my life. That gives me both a sense of empowerment and a sense of responsibility. I don't believe in fate which means that I don't just sit back and wait for things to happen - things happen as a result of the laws of nature and human action. If I want to see a particular outcome then I need to do what I can to influence it, not just sit back and say "well, if it's meant to happen then it will".
Humanism is more demanding than religion. It doesn't give you easy
answers, but it does give you the best answers that are available. This makes it far more satisfying.