It's not uncommon for people to ask whether or not we can trust the Bible. How do we know the Bible wasn't manipulated throughout history by the church to make Jesus into something He never claimed to be? It's a good question and one we must ponder carefully.
I believe we can have great confidence in that what we have in our Bible is what was written by the original writers and that it hasn't been changed. I base my assertion on the fact that we have a tremendous number of very early manuscripts that all attest to the authenticity of the Bible. In fact, the manuscript evidence alone speaks volumes.
The Bible has the most manuscript authority of any book from ancient times. Second place goes to "The Illiad" by Homer. The Illiad has 643 manuscripts to authenticate the words written by Homer. By contrast, the New Testament of the Bible has 24,633 early manuscripts to authenticate the words written by the authors. The New Testament of the Bible has roughly 24,000 more manuscripts than the second most authenticated book from antiquity. The sheer volume of authenticating texts allows one to take and reconstruct the original with a very high degree of certainty as to the original words penned by the New Testament writers. Author Josh McDowell argues that one can take the 24,633 early manuscripts from the New Testament and reconstruct the original to a 99.5% pure text. That's incredible!
The New Testament of the Bible can be relied upon. We can know with great certainty that the words in our Bible are good representations of what the original writers wrote. I believe the message of the New Testament is so important that God providentially worked to preserve the text beyond a shadow of a doubt.
For further research, I recommend Josh McDowell's book "The New Evidence That Demands a Verdict." It provides lots of great research into many of the questions people have about the Christian faith.