atheism is properly defined as a denial of the existence of God in the midst of full knowledge that the true God does indeed exist. Atheism knows God exists; it is quite familiar with that fact, but it says "under no circumstance or situation will I admit to God's existence."
Atheism clearly perceives the fingerprints of God on all of creation, but refuses to admit He is the Creator. Atheism perceives the divine authorship of the TEN COMMANDMENTS, but refuses to admit that God is their Author. Atheism perceives the decorousness and perfection of the TEN COMMANDMENTS, but refuses to admit they are superior to all other laws. Atheism clearly perceives the divinity of the Lord Jesus Christ, but refuses to admit His divinity. If an atheist could see the wounds in the body of Christ and actually feel them with his hands, he would deny that the wounds are there. Atheism is deliberate effort to never admit the existence of God.
Atheism is the ultimate of satanism. Ask satan does God exist and he will deny it. Ask him does satan exist and he will deny his own existence even while in your presence. Atheism holds the Bible in one hand, but deny its existence by denying its truth with the other.