By not having a god-concept, as in Confucionism and Humanism, or by not basing itself on such a concept even if it happens to have one, as in Jainism, many forms of Taoism and most of Buddhism.
There are probably other ways as well.
Those beliefs have a form of spirituality though except for Confucianism and Humanism which are both labelled philosophies. They do not fall into the category of religion. Religion must have morals, practices, spirituality and philosophy. Stopping short on 1 of these does not make it a religion.
Confucianism and Humanism are not recognized as religions according to any person as far as I know. This is why in China they practiced this as communist ideology rids itself of religion and god. Most who do believe in god mix Confucianism with Buddhism often. Many people exclude Buddhism actually which is not fair considering that it is a Natural Theology.
If you sincerely mistake belief in God with spirituality, I suppose that will sound just right. Unfortunately or otherwise, it is not actually true.
I think this is where the problem is.
Religions accept both god and spirituality as to believe in god you cannot have the other. God is not necessary for religion entirely but spirituality(or even the supernatural) is all that is needed.
All religions fall under this branch.