The main truth of atheism is in what it denies.
The atheist says he does not believe in God, and rightly so. Although, he believes in very many things: false gods. He is gullible to believe because he denies God. His position requires much more faith than a believer because he puts his trust in much lesser ends. Here is a list of the things an atheist believes in.
1. his own ideas, or those of others.
2. money.
3. success.
4. pleasure.
5. the material world, the cosmos (necessarily eternal because if it had a start it would have needed a Starter!), evolution (which he has never seen!).
6. fame.
7. space and time.
8. energy.
9. baseball cards.
10. snakes,...you name it!
And they are all cheap substitutes. The atheist is therefore truly a-Theistic in that, and in that only, he denies the One True God, but will believe in anything else! He is willing to accept a pantheon of lesser things to live and die from and for: i.e. gods--false idols. As long as you grant him not to worship, to refuse acknowledgement, adoration and worship of the Universal Lord. He is willing to become mad and even destroy himself, as long and he does not have to obey.
So an atheist can be a hedonist, a sensualist, a materialist, a devil worshiper, etc., anything except a believer that there really is a Lord of all to Whom we owe our allegiance and our life, Who is the very meaning of our existence.
The first commandment is the problem which defines the life of every atheist, his fundamental stance: he refuses the "I am the Lord your God, you shall have no strange gods besides me." And in his craze to reject God he will believe every manner of lunacy and in anything. It is a fundamental state of rebellion.
In that the atheist is much like the Protestant who in his zeal to reject Catholicism is willing to acknowledge the legitimacy of every form of doctrinal aberration and call it Christian as long as it is not under the purview of the Supreme Pontiff. They will accept the authority of every Tom, Dick and Harry, just so long as they ignore and reject the Pope! Anyone can claim to be Christian in every manner of doctrine and moral perversion, just so long as he does not believe in priestly authority ordained by God in a humanly structured Church inspired and guided by God. Men will tolerate any chaotic inspiration in any type of heated celebration but do accept that a man ordained by Christ Himself to bring God to the earth should efficaciously say: "This is my Body,...this is my Blood,...do this in memory of me!" or "May God give you pardon and peace and I absolve you from your sins, in the name of the Father, and of the Son, and of the Holy Spirit. Amen."
That is the defining and common error of all heresy be it "atheist" or "Christian", you can believe in anything accept the Truth of God as ordained by God. It is not a lack of faith. The infidels have too much faith; faith in the wrong things, because they have rejected God and the Church which he founded to guide us in His truth with the assistance of His sacred ministers. That is the thesis of the renowned physicist and award winning author Father Stanley Jaki's book Science and Creation.
No man lives without a god. You just have to be careful to choose the right One. And, yes, there is but One: Jesus Christ, who is vouchsafed by His One, Holy, Catholic, and Apostolic Church which subsists in the Catholic Church. Amen.
Start at the start, with the first commandment. Acknowledge God!!! Acknowledge Christ and your personal Lord and Savior and accept Him. Then you will be in a position to accept and cherish the other nine (and the law He will thence write incessantly on your heart by his sweet guidance and constant companionship: like a Shepherd He leads His sheep! guiding gently, sweetly and surely!). That, my friends is the Catholic religion bequeathed to the entire humanity by Christ through the Church.
And, yes, go to Church and look for Jesus Christ there. He is alive and you will find Him fully only there and He will give you life, within the embrace of the Catholic faith in the communion of saints and the forgiveness of sins and life everlasting.
Cf. Science and Creation, Jaki. Jaki shows that throughout the history of science it was repeatedly faith which served as the basis for the rational stability necessary for science.