How can one know that the Bible contains the real truth instead of some other religion?
Can you provide any evidence that the Bible, as it is currently worded, contains the real truth? In the light that the Bible has been copied over and over many times as well as having been translated many times.
Who is "email"?
To answer your question, I believe careful reading of the Bible clears up all the confusion (Ephesians 3:3-5; II Timothy 3:16-17). If we say that we cannot read the Bible and understand it, then we indict God (Psalm 119:73)! The trouble occurs because man has developed many traditions, which do not necessarily agree with Scripture (Matthew 15:1-9). Whether they have bound where God loosed, or loosed where God bound, they have caused division through hundreds of years of following the traditions of their fathers, while creating new ones themselves.
Personally, I believe today is not very different than days gone by:
Now, as to whether the Bible represents the Word of God, I believe you can test that two ways. One, you can read it and compare it the other competing books, Quran, Book of Mormon, etc. Some people can recognize a genuine difference immediately. I tip my hat to them. I am more of a cynic. I look to the objective evidence. In this arena, the Bible stands head and shoulders above all other books. The internal consistency, historical accuracy, internal claims (claims to be verbally inspired), and surviving chain of textual transmission is orders of magnitude beyond any other ancient document, religious or otherwise. Keep in mind that most reputable translations are based on the original language, not another translation, and we have remnants of Scripture dating to within almost 100 years of the original autographs. That is unprecedented among other books! Most others were not even written for several hundred years after the related events.Thus says the LORD: "Stand in the ways and see, And ask for the old paths, where the good way is, And walk in it; Then you will find rest for your souls. But they said, 'We will not walk in it.' (Jeremiah 6:16)
We have a brief article on the facts here:
A good library or Bible bookstore should house many more books detailing the hundreds of Christian-evidences book, most of which will detail this very concern.
Once the textual transmission is verified, the fulfilled prophecies (II Peter 1:19-21) and internal consistency (Titus 1:1-2, 9), prove its origin beyond doubt.
Lastly, your concern is one of historical truth. It cannot be proven like a science. There is not mathematical proof or experiment that will yield empirical knowledge. It is comparable to proving that George Washington existed. You have to carefully examine and weigh the evidence to determine the most likely explanation of the evidence. There will always be some unanswered question, but the overwhelming amount of evidence demands the inspiration and integrity of our modern Bible.
I pray this helps. Please let me know if you have any other questions, or if I can help in any other way.
May God help us to have a sincere love of truth,