Simply believing that something is true doesn't make it true. People believe a lot of things. Each believer convinced that they are right and the others are wrong.
Same argument back at you. A lot of unbelievers believe something is not true, but that doesn't make them right either.
Come on! Convince me you bunch God haters.
"Keep thy heart with all diligence; for out of it are the issues of life." (Prov 4:23)
