It might seem wiser to start off slow and easy just simply arguing directly “that atheism is no less valid a choice than theism”. However, since the atheist position by definition is wholly negating of the theist (not to be confused with deist) and vice versa, the limits of this tactic are apparent. Moreover, it is predicated on the assumption that theists might be amenable to reason. A very long shot indeed since the theist position is arrived at in the absence and maintained through the suppression of reason.
Most importantly, it’s simply not true. Atheism and theism (not to be confused with deism) are NOT equally valid choices. As little as, Astronomy and Astrology, Chemistry and Alchemy, Evolution and Creationism are equally valid choices.
The folly of compromising intellectual honesty for what can scantily be gained from tiptoeing around theists’ dearly held delusions has been borne out by history. It also has deadly consequences e.g. the Catholic Church’s undermining the fight against AIDS in Africa by condemning condom use.
More information about text formats