1. (

• atheistic ,
• atheistical ,
• unbelieving

) rejecting any belief in gods ;

2. (

• nescient ,
• unbelieving

) holding that only material phenomena can be known and knowledge of spiritual matters or ultimate causes is impossible ;

3. (

• disbelieving ,
• skeptical ,
• sceptical ,
• unbelieving

) denying or questioning the tenets of especially a religion; "a skeptical approach to the nature of miracles" ;