Each book changes your life in some way. Even the very simple have something to say that, if you let it, gives you an example of life, at least for those in similar circumstances to those in the story.
I once read that the process of writing and reading is the most intimate of relationships because two minds communication without the hinderance of the physical form, location or time. I have insights into Charlotte Bronte's mind because I read her story Jane Eyre. Time and distance has no hold on that relationship even if it is all one way.
The letter to the Roman's written by Paul of Tarsus was instrumental in cementing my faith and outlook on life. He very clearly (in great detail from several angles) sets out the Christian life, how we can claim inheritance as God's children and most importantly how we should behave in response to that gift.
In that book we see Paul's complete commitment and reliance on God. We see his thoughtful and precise mind that can picked the bones from an arguement, breaking it down, making his position clear. We find out about all those who he cared for and were devoted to him and the gospel in return.
Two thousand years, culture, language and a world are between me here and him there, but I still know his mind. That's the sort of time travelling anyone can achieve, all they have to do is open a book.