Agnostic (noun)

A person who believes that it is impossible to know whether there is a God or not.

Origin:

Late 19th century: from greek agnōstos "unknown" + -ic.

Examples:

1. He was an agnostic, he couldn't decide whether to believe in God or not.
2. She was an agnostic and had no opinion about the existence of God.
3. He was an agnostic and believed that the existence of God is unprovable.
4. The agnostic philosopher believed that the question of God's existence is beyond human understanding.
5. He was an agnostic and does not claim to have knowledge of the existence or non-existence of God or gods.