There are two main methods of translating the scriptures--

1. Word for word.
2. Thought for thought.

1. The word for word method (formal equivalency) says that since God promised to preserve His words, then we must have them; and taking the best manuscripts, translating them (as best as can be) word for word into another language (in this case English). This is the method used for the King James version of the Bible.

2. The thought for thought method (dynamic equivalency) says that we can't possibly have all of the correct words of God (because there are some corrupted texts), but God must have preserved what He meant; so they try to translate, not words, but thoughts.
Thought for thought translation is not possible without first having all of the correct words. If you do not possess all of the right words you run the risk of getting the wrong though or meaning.

For example:

"I am going to church."

"I am not going to church."

Some will say, "but when I read the (NIV, etc..) it seems so much clearer." But they do not realize that when the doctrine of the preservation of the words of God is doubted and pushed aside, and the preservation of the "thoughts" of God is preferred; it opens a door for the translators to make a passage say what they think God meant. So, in the reading of (the NIV, etc..) you may very well understand it better, but what you are understanding may be just the commentary of the translator telling you what he thinks God said in a certain passage. The translator becomes a filter between you and the text.
If what you read in the authorized version seems to be difficult to understand, it is probably because the translators followed the method of "word for word" translating. The text was originally written in another language, so, doubtless, their will be passages that don`t seem clear to us; but there were things in the Bible at the time of writing that were hard to be understood:

2Peter 3:16, "As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction."

The translators of the NIV decided to clarify what God said in 1Corinthians 7:1 when they took it from this:

"it is good for a man not to touch a woman"

" it is good for a man not to marry a woman".

This is not what this passage is saying at all. The word that is translated "touch" here has an immoral connotation; it surely doesn't mean marriage.
Translators can take a passage and make it say whatever they want it to say, if they believe God did not preserve His words.

2Ti 3:16, "All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:"

When the writers of the 66 books of the Bible sat down and penned them, they were guided by God's direct inspiration. They did not make a mistake. They did not pen any errors. But a problem has arisen, because there have been some very old manuscripts surface in the last few hundred years that disagree with the ones that have always been used. The Bible is clear in that God will preserve His word (see also Psa 12:6-7); so, why don't all of the manuscripts agree? Let's look at the two accepted groups of manuscripts:

The Minority Text

The oldest manuscripts make up the text for the newer versions in what is known in the realm of textual criticism as the Eclectic Text, or what we call the "Minority Text". They are called the minority texts because there is relatively few of them compared to the "Majority Text" manuscripts.
Many scholars believe that since these are the oldest, they must be the best. This is usually the approach taken with any ancient document or writing, because it is reasoned that texts become corrupted through copying. It sounds reasonable, so let's look at these texts to see if they are the best.

The two major texts are Vaticanus and Sinaiticus. These two manuscripts form the basis of the Eclectic Text. They have their roots in the Catholic church (one found in the Vatican, and the other found in a monastery). We will look at their history in more detail later.
Suffice it to say that Vaticanus and Sinaiticus disagree with each other 3000 times in the Gospels alone. The book Codex B and It's Allies (by Hoskier) documents every one of these errors that are found in Vaticanus and Sinaiticus.

The papyri (papyrus, papyruses) dates back to the second century, they are some of the oldest manuscripts that we have.
Of Papyri #66, it is known to contain 200 nonsense readings; and even the textual critic Bruce Metzger, who defends the Eclectic text, says that P66 "contains about 440 alterations introduced between the lines over erasures and in the margins most of them appear to be the scribe's corrections to his own hasty blunders." "Several passages present unique readings that previously had not been found in any other manuscript" This doesn't sound like older is better. It has 900 clear, indisputable errors in the Gospel of John. Is this a credible witness? No.

P46. the textual critic Colwell says that the scribe made deliberate changes in the text.

There are a group of five manuscripts that are believed to be the oldest because they are written in all capitals, and not lower case as all of the other ones. These "capital letter manuscripts" are called Uncial manuscripts. They contain 45 differences in the Lord's prayer alone; and 32 out of the 45 times they are in disagreement. They are the only ones with those readings out of the over 5000 in existence.

Of one manuscript called "Codex Beze" (or Besae), Bruce Metzger says, "No manuscript has so many and such remarkable variations from what is usually taken to be the normal Greek new testament text"
Hort (of Westcott and Hort) mentions "the prodigious amount of error" in this text.

These are a few examples of the manuscripts that make up the Eclectic (or minority) text. Is this the preserved Word of God? How could any rational person (let alone scholars) trust themselves to a group of manuscripts that are so contaminated with error?

The Majority Text

The second group of manuscripts are what we call the "Majority Text" (Byzantine Text, Textus Receptus, etc..). They are called the "Majority Text" because they comprise most of the biblical manuscripts in existence. These manuscripts were used in the translation of the King James Version.
There are some 5000 ancient Greek manuscripts in existence, and between 85-95% agree with each other (these are the ones we call the "Majority Text"). You can't go for quality over quantity because the oldest ones (Vaticanus, Sinaiticus, etc..) are known to contain erroneous errors and are very much disputed. The quantity of the majority text is undisputed.

Consider the manuscripts of the majority texts, they come from many different centuries (10th, 11th 12th), from different locations (Africa, Asia, Europe) and there are several hundred that agree together against the few "oldest" texts (i.e.. Vaticanus and Sinaiticus, P66 and others). Which ones are we to believe. These majority texts do not contain such errors as late additions. The only people who say that they do are the textual critics who follow the few "oldest" texts that have omissions.

God never half did anything. Why go to all of the trouble to inspire the "original autographs" if He was not going to preserve them anyway?
The key is faith. "the just shall live by textual criticism, by accumulation of scientific knowledge?" No. The just shall live by faith! Let God be true and all men liars.

Click here for a timeline of the manuscripts down through history.

The Origional Manuscripts?

Everyone agrees that the originals are inerrant. This is not an issue. The issue for us today is whether we have the infallible Word of God today.
The word infallibility was historically used in reference to existing manuscripts. Throughout the centuries, when Christians spoke of the infallibility of the scriptures, they were speaking of the Bible that they held in their hands.
The infallibility of the Bible has always been defended by Christians throughout the church age; but a relatively new concept has been introduced recently. New manuscripts were found, and Christian leaders saw that some of them differed from the ones that have always been used. They then decided that they could no longer believe in the infallibility of the Bible that they hold; but the problem they had was that infallibility has always been taught. So the new thought that was introduced (by men such as Benjamin Warfield...) was that it isn't the Bible as we have it today that is inerrant and infallible, it was the "original autographs".
This is a way to escape questions arising from supposed difficulties that arise from the Bible that we use today. "We are not defending our Bible, we are defending the originals" this is a safe statement, because no one can scrutinize the originals, because they don't exist. It is a form of compromise.