First of all, everyone, everywhere is a "believer" - we all have a "religion" of one type or another, even if we say that we don't believe in any religion! That is being "anti-religious".
An Atheist is a believer - he "has faith" that there is no God, and therefore no "True Religion".
Christians (at least most) believe that the Holy Spirit is the second person of the Holy Trinity (God the Father, God the Son, and God the Holy Spirit - three persons, one triune God).
Some Atheists, and others, have their own "Unholy Trinity". It is the belief in "Me, myself and I"!
One who parties and is always in search of fun and leisure is a Hedonist. His "Unholy Trinity" is "Comfort, pleasure and material things" (I know, I was a member for a while!).
The extreme to the other side might be Sadism or Sado-Masochism, with the "Unholy Trinity" of "Suffering, pain, and possibly even suicidal thoughts" or some other unhealthy, unproductive or downright illogical, distorted, destructive and/or dangerous worldview.
No matter what someone believes, it is still their "religion".
Anyway, for those who seriously wonder if we can ever really know "The Truth" about God, religion, etc., consider for just a moment or two, this statement:
"Nothing is true."
Now ask yourself this question:
"If 'Nothing is true', than how can someone even attempt to say that statement itself is true!?" After all, if 'Nothing is true', than that statement can't be true either!! So, logically, the more someone tries to declare that statement IS true, the more they have just declared that there really IS a thing called Truth, which means they just contradicted themselves about nothing being true!! Did I thoroughly confuse you yet? : )
As far as "What is the Holy Spirit?", if you want to know the OFFICIAL Christian teaching, for the last 2,000 years, from the Church that Christ (God) Himself established and placed His official "marks" on, and His "fingerprints" all over, visit here:
And for the skeptics, if you're brave enough, or serious enough, and you'd like to perform a completely unbiased, honest, and very SCIENTIFIC experiment to try to prove or disprove this "theory", then try this:
Every day for the next nine days straight, read the prayer below (a "Novena", just like in the Book of Acts Chapter 1, the nine days before Pentecost) as if you really, sincerely DID believe EVERYTHING you read, as best as you can muster, and live it out for the full nine days as much as you know how.
Then, let God, through the power of His Holy Spirit, do the rest, and see what happens! OK, ready? Be strong! In the words of a late, great, and powerful prophet of God - in our very own generation - "BE NOT AFRAID!"
PRAYER FOR THE SEVEN GIFTS OF THE HOLY SPIRIT:
"O Lord Jesus Christ, before ascending into heaven you did promise to send the Holy Spirit to finish your work in the souls of your Apostles and Disciples, deign to grant the same Holy Spirit to me that He may perfect in my soul, the work of your grace and your love. Grant me the Spirit of Wisdom that I may despise the perishable things of this world and aspire only after the things that are eternal, the Spirit of Understanding to enlighten my mind with the light of your divine truth, the Spirit of Counsel that I may ever choose the surest way of pleasing God and gaining heaven, the Spirit of Fortitude that I may bear my cross with you and that I may overcome with courage all the obstacles that oppose my salvation, the Spirit of Knowledge that I may know God and know myself and grow perfect in imitation of the Saints, the Spirit of Piety that I may find the service of God sweet and amiable, and the Spirit of Fear that I may be filled with a loving reverence towards God and may dread in any way to displease Him. Mark me, dear Lord with the sign of your true disciples, and animate me in all things with your Spirit. Amen."
Oh yeah, to be a legitmate, and completely accurate scientific study, you also have to pray it as if you REALLY ARE committing the rest of your life to really know God's Truth and purpose for you! He DOES know when you're taking Him seriously, and when you're not!
"What about an agnostic, who doesn't believe in gods, but doesn't believe that there are no gods?"
I agree with Iano, just below Funkaloyd's post. The agnostic's "faith" is basically the belief that we humans, or at least some individuals, cannot know, with any degree of certainty, that God exists. They have not yet accepted, or acted on, the possibility that a person really CAN know God, if they really, honestly, allow Him to reveal Himself to them - in one way or another: through the undeniable, infinitely intelligent design in nature, through reading the scriptures and other HISTORICAL evidence, particularly "Christian Apologetics" (like http://www.peterkreeft.com/topics/christ-divinity.htm), through "infused knowledge - straight from God, or any way He so chooses to reveal Himself).
Or, as one of the world's greatest resources, the Church God Himself established, states:
"Agnosticism assumes a number of forms. In certain cases the agnostic refrains from denying God; instead he postulates the existence of a transcendent being which is incapable of revealing itself, and about which nothing can be said. In other cases, the agnostic makes no judgment about God's existence, declaring it impossible to prove, or even to affirm or deny."
"Agnosticism can sometimes include a certain search for God, but it can equally express indifferentism, a flight from the ultimate question of existence, and a sluggish moral conscience. Agnosticism is all too often equivalent to practical atheism."
And for more about the undeniable, infinitely intelligent design in nature, the first big step to finding the "Fountain of Truth", visit:
What a great perspective on the Holy Spirit. You are right, we need to recieve the Holy Spirit (God) - as Jesus said, "whoever abides in me, I will abide in them". Pretty amazing that God wants to share His divinity with us, just like (although maybe not exactly like) he did with the Twelve (apostles), as they performed healing miracles, and raised people from the dead - their "credentials", and public witness of having the authority of God, that Jesus (God in the flesh) entrusted them with! Jesus also called the apostles to particpate in His miracles (magnification of the loaves, catching a net full of fish, John 21, etc.)
The Apostle's Creed associates faith in the forgiveness of sins not only with faith in the Holy Spirit, but also with faith in the Church and in the communion of saints. It was when he gave the Holy Spirit to his apostles that the risen Christ conferred on them his own divine power to forgive sins: "Receive the Holy Spirit. If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained."
"Now when the apostles at Jerusalem heard that Samaria had received the word of God, they sent to them Peter and John, who came down and prayed for them that they might receive the Holy Spirit; for it had not yet fallen on any of them, but they had only been baptized in the name of the Lord Jesus. Then they laid their hands on them and they received the Holy Spirit" (Acts 8:14-17).
"On the evening of that day, the first day of the week," Jesus showed himself to his apostles. "He breathed on them, and said to them: 'Receive the Holy Spirit. If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained"' (Jn 20:19, 22-23, Matt.16:18-19). Boy, non-Catholics just don't know what to do with some of these verses, huh? : )
As St. Paul affirms, "Where sin increased, grace abounded all the more." But to do its work grace must uncover sin so as to convert our hearts and bestow on us "righteousness to eternal life through Jesus Christ ourLord." Like a physician who probes the wound before treating it, God, by his Word and by his Spirit, casts a living light on sin:
Conversion requires convincing of sin; it includes the interior judgment of conscience, and this, being a proof of the action of the Spirit of truth in man's inmost being, becomes at the same time the start of a new grant of grace and love: "Receive the Holy Spirit." Thus in this "convincing concerning sin" we discover a double gift: the gift of the truth of conscience and the gift of the certainty of redemption. The Spirit of truth is the Consoler.
"It pleased God, in his goodness and wisdom, to reveal himself and to make known the mystery of his will. His will was that men should have access to the Father, through Christ, the Word made flesh, in the Holy Spirit, and thus become sharers in the divine nature."
The Word became flesh to make us "partakers of the divine nature": "For this is why the Word became man, and the Son of God became the Son of man: so that man, by entering into communion with the Word and thus receiving divine sonship, might become a son of God."