non-religious           
adjective (also nonreligious) uk/ˌnɒn.rɪˈlɪdʒ.əs/ us/ˌnɑːn.rɪˈlɪdʒ.əs/
 非宗教的,和宗教无关的
not relating to or involving religion
  I prefer to send non-religious cards at Christmas.  圣诞节时,我更喜欢寄出不含宗教意味的卡片。 
 They decided to have a non-religious marriage ceremony.
  不信教的,无宗教信仰的
not having a belief in a god or gods
  She grew up in a non-religious family.
 Almost all the people who post on this forum are non-religious. 几乎所有在这个论坛上发帖的人都没有宗教信仰。 
 - More examples
 - My parents wanted me to have a nonreligious education.
 - We live in a largely non-religious society.
 - One of the school's great strengths is its mix of religious and non-religious students.