Is it possible that you are mistaken, and there is no God at all?
Is it possible that the bible is not in any way the word of any God?
Is it not possible that atheists are wrong, and that there IS a God. Is it not possible that the Bible DOES contain God's communications to man?
People make claim to guidance from God in bible interpretation.
Do you take this as an implicit claim that God steered them right?
If the INTERPRETATION is incorrect, the problem is not with God, but with the one interpreting it. Much disagreement amongst Christians comes from topics that do not concern the essentials - as opposed to issues like the necessity to have faith in Christ or practices of basic morality - typically things which the Bible explicitly and clearly teaches, and that classical Christians agree upon, around the world. Look where Christians who take the Bible seriously AGREE. But Christians are failable men and women, and wherever there are passages far less clear, there will be differences of opinion.
Just because a person has a Bible doesn't mean they will ALWAYS accurately understand it. Certain aspects of Scripture God WANTS us to wrestle with, pray more over, seek out the wisdom of those with higher training and study. To the degree one has done these things, particularly in seeking God in prayer, the more likely they will be to correctly grasp the correct meanings, as God leads them. But while led by God's Spirit, we still can't have COMPLETE understandings, as then we would have the mind of God Himself. Clearly there is a hierarchy of what God cares we most understand - as opposed to issues like the age of the earth, the time and scale of Noah's flood, etc. And just because we can't perfectly know many things, there are also many key things that God has made completely clear to us: The ESSENTIALS of what He considers most important!
And just because we can't know certain things with certainty, or can't PROVE them by one of our methodologies, in no way invalidates their truth. The truth of things does not rest upon always being able to prove them. And if one is seeking to prove their way to faith - it doesn't work like that. Ultimately, with some key things, it becomes a matter of sincerely seeking and being entirely open to the truth - however and wherever it might show up, as well as a matter of logical probabilities. Somewhere in that chain of seeking should be at least an experimental seeking of God - even though one might have no current reason to do so. This is a personal quest only the seeker needs to be aware of. This is a thing Scripture reveals, that God honors those who sincerely seek Him. At the end of all of these things is necessarily a gap that can only be connected to God, through the mind and heart through faith. And once faith is placed, certain powerful certainties of understandings DO set in. But the leap of faith required is not a completely blind one, as the probabilities offered, the power in seeking God beforehand, all add up to a huge collective for which it is entirely reasonable to bridge that last gap with faith in God/Christ.
Just to add a challenge: Let's say, one is at the precipice of deciding whether to take a leap of faith and commit themselves to Christ in heart, mind and word. What is the worst that could happen if you did that and the result was NOTHING - EVER. Well, you would be right back to where you are now, right? Nothing lost, eh? Yet you would have been open-minded enough to pursue truth wherever it might be obscured to you. But what if you would instead be placing your faith in a REAL, PERSONAL, and all-powerful God who loves you beyond understandings - THAT would change everything in wonderful ways! And FOREVER! And that is why the Christians here have a certainty in their hearts and minds - it's beyond words to explain - it is our EXPERIENCE with our personal, loving Creator.
Do any unbelievers here really believe that the Christians here are merely self-deceived, unintelligent people who want to believe just any drivel they encounter? Do you think Christians are any less cynical of people, their assertions, their RELIGIONS, etc? Did they not struggle to faith themselves? All Christians were once unbelievers - they identify with that prior experience. And yet they, to a one, testify to something marvelous that their prior life was devoid of: A relationship with God!