• How do we know God exists?  I mean, isn't it just people projecting their own hopes and desires to feel secure?

It's a good question, but I would propose first of all, that if it's possible for people to "project" their beliefs, isn't is also possible for us to "project" our unbelief?  Because the evidence that God does, indeed, exist is rather overwhelming... it really almost takes a decided "act of faith" to conclude that He doesn't.

St. Thomas Aquinas spelled out in the 13th century the "Proofs for the Existence of God" and they're really hard to argue with.  They boil down to what's called "First Cause," and "Intelligent Design."  The universe is built upon "cause and effect," everything was caused by something before it... and the first "un-caused" cause is God.  Even our eighth graders understand the important principle of nihil ex nihilo... "from nothing comes nothing."  In other words, if ever there was a time when nothing existed, nothing COULD exist, because "from nothing comes nothing."  Remember your math, 0 x 0 = 0.  Something had to bring existence out of nothing... we call Him God.

There is an amazing and intricate design we find in Creation... intelligent design... and order.  Order demands intelligence, things didn't come together by chance... God!

The Bible is not a proof for God's existence... the Bible is, rather, information collected and put down in writing for our benefit... to know what God is like.

It's perfectly reasonable to believe that God exists, and sadly there have been few times in histor,y such as our own times, in which the ability to "be reasonable" has been eclipsed.  We put a premium on the emotions... and so, we have people who have concluded that because I don't "feel" God near and obvious, He must not exist.

What I'll often counsel such people... try praying... ask God to reveal Himself to you... and He will in His own way and in a way that will speak to you!  Worship Him... you'll come to understand Him better.  St. Augustine instructed such souls, Believe first... understanding follows.  And that's sound advice... all-too-often, we want "understanding" as a condition to believing, and it doesn't work that way.

If it's truly God's will that we come to know Him and love Him... He's going to help us out, because on our own we simply can't accomplish that.  God has told us Who He is... love right through-and-through... and He'll tell us of Himself.  It's as Our Lord instructed, Seek... and you SHALL find.  Those who don't seek, don't find... so let's start seeking with all the more earnest!