Hi Tammy,
Your post is interesting. My theory of the existence of God is that he does exist but within the mind of believers. If that theory is correct it should show up in a couple different ways. There should be nothing that we can objectively measure that would indicate the existence of God as a real external entity. For example the existence of Pluto was theorized before it was actually viewed. The theory the backs our understanding of gravity was used to calculate Pluto's influence and infer existence and then used to actually spot Pluto in the night sky over Flagstaff, AZ.
The second thing that should be true, if my mind-God-theory is correct, is expressions should tend to be ego-centric. I say 'ego-centric' only because I don't know another way to express the idea. I am not meaning to use this phrase in a negative way -- just that thoughts about God should self-reflect. God, in this case, should know you, answer to you, be an intimate companion.
Saying God exists within the mind of believers only, may seem to diminish his stature, but I actually don't think so. It makes God exactly as powerful as the believer is and it turns out humans can accomplish some pretty darn amazing things -- like Ghandi standing up to one of the most poweful nations on earth. Or the monks in Burma taking huge personal risks to engage in political protest.
Here are a few quotes from your post that seemed to me to fit these two categories, first the self-reflection...
"Christ has always been my lifeline. Doubts that I have ever had, have always brought me back to Him. Originally mainly from what He taught; now from what He teaches and speaks. (present tense) I do not believe He is real. I know that He is."
I was particularily struck by saying he speaks to you in the present tense. I assume you don't mean you're literally hearing voices. It seems more like you're saying his teaching resonate with your life in the here and now. Is that what you mean? Also the assertive phase "I know" speaks to internal knowledge and certainty. If my theory is correct, for you to deny the existence of God at this point, would be to deny your own existence. Given that, atheism is simply not going to be rational in this context.
On the inability to objectively measure the existence of God...
"One person cannot prove to another person that there is God. That sort of imperical proof that non-beleivers are asking for. Because you cannot prove the spiritual with tools meant to measure the physical. You have to use different tools."
On the surface it looks like a simple acknowledgement that settling the question of the existence of Pluto is a different task than that for God. Adding the bit about "different tools" and "spiritual tools" is interesting. Some given to thinking in terms of the concrete and literal would simply say these phrases have no real meaning. But to me it more indicates a struggle with trying to express something you know, in a near absolute sense, yet cannot be separated from yourself as an individual. One of the differences that strikes me between believers and non-believers is the degree of self-knowledge. Many believers are certain, they know with little doubt, God exists. Non-believers in almost every case I have observed will say, that they are not certain it can be proven God does not exist.
Lastly, the rational mind...
"But other people lose faith, or set their faith aside, because they do not like what God is (or is not) doing, according to what man has taught them about God. So usually, it is in a false god that they have lost their faith."
Some non-believers might jump at statements like this, to say the conclusion you've reached misses the obvious -- namely that God does not exist -- but even worse it imputes bad motive on the non-believer. But I see this differently. I see this as the believing mind struggling to understand what is essentially a non-rational concept. If you know that God exists, why then do others not believe? This can be made all the more confusing when you meet and interact with non-believers, many of whom you'll discover think and act in much the same way as believers, have the same range of likes, dislikes and morals, etc.
The human mind is constantly seeking to be rational. To make sense of the world around it. For example where your optic nerve connects to the back of your eye it creates two blind spots in your field of vision. But you don't notice them, because your mind simply fills in the void. Other examples of this occur where one is deprived of good information to the senses. You'll see something off in the distance, but not really well enough to recognize it, your mind will just make something up until you get closer to the object. In this context your believing mind is forcing you to come to some conclusion that remains rational. If the non-existence of God is non-rational it must be rejected.
Cheers,
-Randy