The Bible, as it was originally revealed by God and written down by men in God's name, being the God-inspired Word of God, is free of mistakes and as such cannot have any contradictions. God is a God who cannot lie; instead He proclaims truth and therefore His Word is absolute truth and inherently accurate (cp. 2 Timothy 3:16; 2 Peter 1:20,21).
However, we do not hold the originally revealed Word of God in our hands, i.e. we do not have the originals of the Holy Scriptures before us but instead we rather have translations or revised versions of translations. If there appears to be a contradiction in the Bible, the major cause will be in one of two points (sometimes in both of them):
1. The contradiction is caused by a mistake in our own understanding of what we read.
2. The contradiction is caused by a mistake in the translation.
Quite frequently mistakes occur in our own understanding, especially so when we have allowed ourselves to be influenced by traditional teachings and picture or paintings which are not in agreement with the information conveyed in the Bible. The contradictions which show up in such a situation are mostly not even apparanet contradictions between various statements in the Bible but rather contradictions between the truth revealed in the Bible and the information we have held to be truth because of other teaching or doctrine. In such case only a return to what the Scriptures reveal will enable us to have the truth and to be able to proclaim it to others. How many people believe something, how many scholars have propagated something, is irrelevant and not the decisive factor about truth.
In the case of contradictions which remain even after understanding what is said correctly, the cause must be a mistake in the translation. Often, a closer look at the translation in comparison to the older texts in the biblical languages Hebrew or Greek is sufficient help in order to solve the apparent contradiction.
In general it is very important to read the Bible with the greatest care and with more of an attentive attitude than is generally found (if at all). We must come to the Word of God with the proper reverence, and we must, with a heart of meekness and humbleness, allow God to speak to us via His wonderful Word. We must observe basic points when reading, such as not reading something into a passage or leaving something out, such as leaving statements rest within their context, etc. God was accurate in what He revealed and how He it was revealed and then written down. We must be accurate in our reading. Then God can and will enlighten the eyes of our understanding of His Word by means of His holy spirit within us.
In the Bible we have the Word of God -- that Word which He magnified above all His name (Psalm 138:2).