Synonyms and related words :
atheist, atheistic, creedless, faithless, heathen, heretical, incredulous, infidel, infidelic, irreligious, minimifidian, nonbelieving, nullifidian, pagan, questioning, quizzical, repudiative, skeptical, unbelieving, unchristian, unconfident, unconverted, unconvinced, without faith,