Humanism is the approach to life based on rational thinking and includes ethics based on our shared human values and on human compassion. If you live life without religion and strive to do good within society just for the sake of doing good, then, you are a natural humanist. Humanism's core belief is that everything has a natural cause rather than a supernatural cause, therefore it falls under the banner of philosophical naturalism and the vast majority of humanists are atheists. Humanist activists typically battle for human rights and for secular politics. Secularism, promoted by secularists, is the belief that religion should be a private, personal, voluntary affair that does not impose upon other people. Public spaces and officialdom should therefore be religion-neutral. Secularism ensures that religions are treated fairly and that no bias exists for a particular religion, and also that non-religious folk such as Humanists are treated with equal respect. It is the only democratic way to proceed in a globalized world where populations are free to choose their own, varied, religions.
“It is my deep conviction that pure humanism will be the religion of the future, [of] man — all of life, sanctified and raised to the level of a moral value.”
-- Ernest Renan (1848)