ATHEISM IS NOT UNBELIEF
(Apistia).
From the perspective of Jesus (YHWH God), the world is atheistic or populated by naturally born atheists (without any god at birth) and by former atheists who grow up to choose other gods or to reject Jesus (YHWH God) to become apistheists (theists without belief).

Ephesians 2:12 ASV
(12)  that ye were at that time separate from Christ, alienated from the commonwealth of Israel, and strangers from the covenants of the promise, having no hope and without God [ATHEISM] in the world.

I distinguish 3 main types of Atheism: birth or natural atheism, biblical atheism, and unbelieving atheism.

Atheism comes two Greek components:
a=without and theos=god
From there, men revolve around the word to voice out unbelief which is not hinted anywhere in the etymology of the word.

ATHEISM IS NOT UNBELIEF

1. Birth Atheism 

At birth, we are born atheists because we lack the faculty to choose the Hebrew God (Jesus) or a pagan god. As we grow up, we develop the faculties to not choose or to choose between God and gods.

>>>>Many atheists are not at all opposed to belief in gods, they simply don’t themselves participate. It would be confusing and counter-productive to ascribe to them an ideology they don’t hold. Alas, that’s the kind of thing stupid people are apt to do. Carl Smotricz.>>>>

2. Biblical Atheism

When the born atheist hears the voice of Jesus and follows after Him, the born atheist does not become a theist because, as a believer in God (Jesus), the born atheist is forbidden to also choose and follow another god of any kind (the beast, a spiritual leader, a graven image, anything or anyone whom a man bows to and obeys in religious matters).
A follower after Jesus is a biblical atheist, or a divine atheist.
Atheist because if we bow to another kind of god besides Jesus we become a theist, one who worships any god besides Messiah Jehovah, Jesus.

3. Unbelieving Atheism

When the born atheist does not hear the voice of Jesus, rejects His voice to follow oneself or another voice to do his will, to prostrate or to bows to another, the born atheist has chosen theism, which Jesus forbids, to become a theist.

4. God (Jesus) is the Atheist.

Jesus does not bow to Satan, to men, to the works of His hands and declares that there is no God (atheism) besides Him in Isaiah 45:21, et cetera.

4. Antitheism

Anti-god with the idea of causing harm.

FLASH BIBLICAL NEWS!
From the point of view of God, contrary to popular belief, atheism or atheist is not a bad word. Ephesians 2:12

An atheist (without god) is NOT someone who does not believe in any gods or God, as the modern secular unbelieving atheists claim the word to mean (Ephesians 2:12).

Being an atheist in the classical sense of atheism is an unnamed doctrine that Jesus (God) has enshrined in the first two of the ten commandments (words).

God had pleaded with the Israelites to be atheists but they embraced the theism of the world (Deuteronomy 6:14).

Deuteronomy 6:14 ASV
(14)  Ye shall not go after other gods, of the gods of the peoples that are round about you;

Exodus 20:1-6 ASV
(1)  And God spake all these words, saying,
(2)  I am Jehovah thy God, who brought thee out of the land of Egypt, out of the house of bondage.
(3)  Thou shalt have no other gods before me.
(4)  Thou shalt not make unto thee a graven image, nor any likeness of any thing that is in heaven above, or that is in the earth beneath, or that is in the water under the earth:
(5)  thou shalt not bow down thyself unto them, nor serve them; for I Jehovah thy God am a jealous God, visiting the iniquity of the fathers upon the children, upon the third and upon the fourth generation of them that hate me,
(6)  and showing lovingkindness unto thousands of them that love me and keep my commandments.

Atheists of today has been scaring off believers with their brazen unbelief asking for proof for the existence of any gods.

It is time that they bring proof of their unbelief, if they have any.

Apistheism or Apistheist is the word which expresses unbelief: apistia is unbelief, theos is god.