Keep on playing.
I believe that every able-bodied human has the capacity to understand everything that is necessary for him to understand, and that the reason this is true is that the most "true" interpretation of reality is that which is directly experienced and therefore independent of rationale and abstraction. I believe that this is the only sort of information that can be absolutely known (i.e. known through direct and perfect means, which is different than knowing through indirect means such as evidence or 'proof').
I believe that you are close to right, if not right exactly.
That still doesn't answer the question of scientific proof.
Salvation by believing in Jesus is the only way. That salvation comes through reading or hearing the Word of God, only... no other way.
However, since God created the workings of the universe through speaking them into being, there just might be a whole lot of people who will hear God's word even though they don't read the Bible, and are saved anyway. BUT, BUT, BUT, don't depend on this for salvation. After all, hearing the Word of God through nature doesn't present very much clarity. Read and believe the Bible.
You're speaking of the Christian god. There are thousands of other gods all promising all manner of things in return for your faith. Who is to say one god is greater than any other? The followers of each all proclaim theirs is the greatest, but they all can't be right. In fact, the rules most religions build up around their god preclude the possibility of everyone being right:
'Allah is the one true god and Mohammad is his prophet.' -Islam
'I am the lord your god, you shall have no other gods before me.' -Christianity
These are just two of the most popular religions today, and despite the fact that Islam proclaims to worship the same god as the Christian god, the followers of these religions have a long history of killing each other over 'worshiping the wrong god.'
I don't find compelling any religion's case that their god exists, let alone that he is the sole god. The whole 'but only I can bring you salvation' bit each religion throws in sounds desperate, like a used-car salesman who really needs to make his quota this month to keep his job.
The proof is in the nature of the god, and what you can find out about him/her/it.
For example, if somebody walked up to you and said, "I am God," you might answer, "prove it." If he takes off his hat and pulls a rabbit out of it, you might say, "I've seen that trick before."
But if he takes you throughout hospitals that have thousands of sick people in them, and heals everyone of them before your eyes, and is killed and rises from the dead, and floats up into the air and is hidden in the clouds, even out of the sight of radar, you might be on your way towards being convinced slightly.
Years later, if your grandson hears the story from you, he might not believe it. But if you show him the book that talks about this, and you show him how the book came into existence in a way impossible for a book like this to come into existence, he might still not believe. He still might think the book is a hoax.
This is a little about the Bible, and the God that it portrays. If you examine the history and strong tradition of how the Bible came into being, you will see that it is a book that is impossible to exist. This being the case, the God who caused the impossible-to-exist book to actually exist and be spread across the world like the Bible has been, must be the true God.
Studying the history of the Bible (or any book) might entail a lot of time and work in areas that are not your expertise, and are not something you want to get started in. So, you check out what the Bible scholars have to say.
The choice is still yours. You can believe them or not. But if you do the examination yourself, and if you are of a sincere mind, truly wanting to find God, you will have to agree at least, that the God of the Bible is One that is exceedingly more probable to exist than any of the others, even if you don't believe in Him.
The choice will always be yours, at least until He comes to you in person, and proves to you Who He is, in the ways that only a God can.
The bolded selection above makes no sense. If something said to be impossible exists, then your assumption that it was/is impossible is wrong. That being said, since it does exist and is therefore obviously possible, then it does not in any way constitute proof that there is a god, nor does it constitute proof that God created the book.