You know I've been a Christian for over 40 years now. And every so often, it seems like every 5 years or so a new group comes along and tells us the Bible has gotten changed or corrupted along the way. The other thing that is often said is that God changes things over time, but I see just the opposite in the Bible.

The Bible says...
Isa 40:8 The grass withers, the flower fades, But the word of our God stands forever.
1Pet 1:25 BUT THE WORD OF THE LORD ENDURES FOREVER." And this is the word which was preached to you

Now if the God who created the Heavens and everything in then, every grain of sand, every molecule, every star, every galaxy, every person of the Earth can control all of these
billions upon billions of things, I think he can certainly control what goes into the Bible. If the God who controls the wind and seas and the courses of all the rivers on the earth
can keep track of these things, I think he can take care of the Bible.

2Tim 3:16 All Scripture is inspired by God and profitable for teaching, for reproof, for correction, for training in righteousness;

Nothing in the Bible is there by accident, nothing is left out that needs to be there and nothing is included that doesn't need to be there. People who try to change things in the Bible will pay an extremely high price.
Rev 22:18 I testify to everyone who hears the words of the prophecy of this book: if anyone adds to them, God will add to him the plagues which are written in this book;
Rev 22:19 and if anyone takes away from the words of the book of this prophecy, God will take away his part from the tree of life and from the holy city, which are written in this book.

One newer church talks alot about the Bible being corrupted, so they wrote their own book to go by. This book is currently in it 31st revision. (to correct mistakes no less) The Bible is still in it's original form.
I have actually seen the real dead sea scrolls a few years back on exhibit, I didn't get to touch them, but I got to look at quite a bit of them. I have also seen the codus synodus in the Smithsonian Institute from the 7th century. I understand the Vatican also has a 7th century Bible. The dead sea scrolls are from the 1st century and a Bible found recently in Ireland has been carbon dated to the 2nd century. All of these have been scoured over many times by scholars, both believers and non-believers and unanimously they agree that our current Bibles are extremely accurate to the original texts. I myself own a Bible printed before the American civil war. I even read it on occasion. I have tested it against specific verses in my 2010 Bible. So far I haven't found any discrepancies.
If the Bible has somehow gotten corrupted over the years, who or what should we put our faith in. If God is a liar and his Word doesn't stand forever, who's version should we choose to believe, there are plenty of alternatives, and they are all different. It must be nice to be able to pick and choose which verses in the Bible are wrong or incorrect. Especially if I disagree with a few of them. (Trust me, there are a few verses I wish weren't in the Bible sometimes)
This is how many cults get started, either mis-quoting scripture or writing their own.

The other thing is God does not change.
Heb 13:8 Jesus Christ is the same yesterday and today and forever.
James 1:17 Every good thing given and every perfect gift is from above, coming down from the Father of lights, with whom there is no variation or shifting shadow.
1Sam 15:29 "Also the Glory of Israel will not lie or change His mind; for He is not a man that He should change His mind."
Mal 3:6 "For I, the LORD, do not change; therefore you, O sons of Jacob, are not consumed.
Psa 102:27 "But You are the same, And Your years will not come to an end.

If God is the Word and the Word is God, and God does not change, then neither does the Word.
What kind of capricious God would he be if he changed the rules all the time? If the rules changed from generation to generation or person to person, if all of were held accountable to different standards, would that be fair? How could we be held accountable to changing rules?

No, God is always the same.. and his Word is always the same.
Anyone who comes along with some "new discovery" or some new revelation that the Bible was wrong all along, or at least for the last few hundreds years is calling God a liar.

Mark 12:24 Jesus said to them, "Is this not the reason you are mistaken, that you do not understand the Scriptures or the power of God?
Gal 1:8 But even if we, or an angel from heaven, should preach to you a gospel contrary to what we have preached to you, he is to be accursed!
Gal 1:9 As we have said before, so I say again now, if any man is preaching to you a gospel contrary to what you received, he is to be accursed!

What's really ironic is that the "Bible is corrupted" arguments are usually made out of necessity rather than actual sincerity. Case in point: Mohammad was illiterate and so did not know what the Bible actually said; he desired to be a prophet to the Catholics and the Jews; he claimed the Bible is good and told his followers to respect it. The only references to the Bible in the Qur'an are positive ones.
It is only due to Scripture's opposition to messages such as Mohamad's that Muslims have repeatedly argued that the Bible must be flawed. There is no statement as to when or how this transpired; it is simply asserted because the Qur'an is based on Scripture, which is sadly ironic since Scripture invalidates the Qur'an.

HOW WE GOT OUR BIBLE
by Charles C. Ryrie

The question of which books belong in the Bible is called the question of the canon. The word canon means rule or measuring rod, and in relation to the Bible it refers to
the collection of books that passed a test of authenticity and authority; it also means that those books are our rule of life. How was the collection made?

The Tests for Canonicity
First of all, it is important to remember that certain books were canonical even before any tests were put to them. That’s like saying some students are intelligent before any
tests are given to them. The tests only prove what is already intrinsically there. In the same way, neither the church nor councils made any book canonical or authentic; either the book was authentic or it was not when it was written. The church or its councils recognized and verified certain books as the Word of God, and in time those so recognized were collected together in what we now call the Bible.
What tests did the church apply?

(1) There was the test of the authority of the writer. In relation to the Old Testament, this meant the authority of the lawgiver or the prophet or the leader in Israel.
In relation to the New Testament, a book had to be written or backed by an apostle in order to be recognized. In other words, it had to have an apostolic signature or apostolic authorization. Peter, for instance, was the backer of Mark, and Paul of Luke.
(2) The books themselves should give some internal evidences of their unique character, as inspired and authoritative. The content should commend itself to the
reader as being different from an ordinary book in communicating the revelation of God.
(3) The verdict of the churches as to the canonical nature of the books was important. There was in reality surprising unanimity among the early churches as to which
books belonged in the inspired number. Although it is true that a few books were temporarily doubted by a minority, no book whose authenticity was doubted by any large number of churches was later accepted.

The Formation of the Canon
The canon of Scripture was, of course, being formed as each book was written, and it was complete when the last book was finished. When we speak of the “formation” of
the canon we actually mean the recognition of the canonical books by the church. This took time. Some assert that all the books of the Old Testament canon were collected and recognized by Ezra in the fifth century B.C. References by Josephus (A.D. 95) and in 2 Esdras 14 (A.D. 100) indicate the extent of the Old Testament canon as the thirty-nine books we know. The discussions by the teaching-house at Jamnia (A.D. 70—100) seemed to assume this existing canon. Our Lord delimited the extent of the canonical books of the Old Testament when He accused the scribes of being guilty of slaying all the prophets God had sent Israel, from Abel to Zechariah (Luke 11:51). The account of Abel’s death is, of course, in Genesis; that of Zechariah is in 2 Chronicles 24:20-21, which is the last book in the order of the books in the Hebrew Bible (not Malachi as in our English Bibles). Therefore, it is as if the Lord had said, “Your guilt is recorded all through the Bible—from Genesis to Malachi.” And He did not include any of the apocryphal books that were in existence at that time and which contained the accounts of other martyrs. While these book are of value, the canonizers of the period felt that they "did not reveal the divine nature of God". The first church council to list all twenty-seven books of the New Testament was the Council of Carthage in A.D. 397. Individual books of the New Testament were acknowledged as Scripture before this time (2Pet 3:16 and 1Tim 5:17), and most were accepted in the era just after the apostles (Hebrews, James, 2 Peter, 2 and 3 John and Jude were debated for some time). The selection of the canon was a process that went on until each book proved its own worth by passing the tests of canonicity. The twelve books of the Apocrypha were never accepted by the Jews or by our Lord on a par with the books of the Old Testament. They were revered but were not considered Scripture. The Septuagint (the Greek translation of the Old Testament done in the third century B.c.) included the Apocrypha with the Old Testament canonical books. Jerome (ca. Ail 340—420) in translating the Vulgate distinguished the canonical books from the ecclesiastical books (the Apocrypha), which had the effect of according them a secondary status. The Council of Trent (1548) recognized them as canonical, though the Reformers rejected this decree. In our English Bibles the Apocrypha was set apart in the Coverdale, Geneva, and King James versions. The first English Bible to exclude it entirely as a matter of policy was an Amsterdam edition of the Geneva Bible published in 1640, and the first English Bible printed in America (the Aitken Bible, 1782) omitted it.

Is Our Present Text Reliable?
The original copies of the Old Testament were written on leather or papyrus from the time of Moses (ca. 1450 B.c.) to the time of Malachi (400 B.C.). Until the sensational discovery of the Dead Sea Scrolls in 1947 we did not possess copies of the Old Testament earlier than Ail 895. The reason for this is simply that the Jews had an almost superstitious veneration for the text, which impelled them to bury copies that had become too old for use. Indeed, the Masoretes (traditionalists), who between Ail 600 and 950 added accents and vowel points and in general standardized the Hebrew text, devised complicated safeguards for the making of copies. They checked each copy carefully by counting the middle letter of pages, books, and sections. Someone has said that every thing countable was counted. When the Dead Sea Scrolls were discovered, they gave us a Hebrew text from the second to first century B.C. of all but one of the books (Esther) of the Old Testament. This was of the greatest importance, for it provided a much earlier check on the accuracy of the Masoretic text, which has now proved to be extremely accurate. Other early checks on the Hebrew text include the Septuagint translation (middle of third century B.C.), the Aramaic Targums (paraphrases and quotes of the Old Testament), quotations in early Christian writers, and the Latin translation of Jerome (A.D. 400) that was made directly from the Hebrew text of his day. All of these give us the data for being assured of having an accurate text of the Old Testament. More than 5,000 manuscripts of the New Testament exist today, which makes the New Testament the best-attested document of all ancient writings. The contrast is quite startling. Not only are there so many copies of the New Testament in existence, but many of them are early. The approximately seventy-five papyri fragments date from Ail 135 to the eighth century and cover parts of twenty-five of the twenty-seven books and about 40 percent of the text. The many hundreds of parchment copies include the great Codex Sinaiticus (fourth century), the Codex Vaticanus (also fourth century), and the Codex Alexandrinus (fifth century). In addition, there are 2,000 lectionaries (church service books containing many Scripture portions), more than 86,000 quotations of the New Testament in the church Fathers, old Latin Syriac and Egyptian translations dating from the third century, and Jerome's Latin translation. All of the data plus all of the scholarly work that has been done with it assures us that we possess today an accurate and reliable text of the New Testament