It is hard to point to just one book to read and study, so let me answer this way: fix your eyes on Christ as He is revealed in the Scriptures. What I mean by that is get to know who He is and what he has done.  The more we know about the character of God, the more we will trust Him, love Him, and desire to walk faithfully with Him.  One book I would suggest is the Gospel of John.  Why?  The apostle John wrote this letter for a specific purpose. He tells us what this purpose is at the end of his letter.  He writes in John 20:30-31...

Jesus did many other miraculous signs in the presence of his disciples, which are not recorded in this book.  But these are written that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name.

    Did you see what it said?  John wrote this so that those who read this letter would believe and continue to believe that Jesus is the promised Messiah, that he truly is God.  This would be a really good place to start.

   It is also great to see examples.  The bible is filled with examples of people who have lived lives of faith.  It may be helpful to read some of their stories and learn from their mistakes, as well as their successes (i.e. Job is known for his faithfulness and there is an entire book dedicated to him in the Old Testament).  One other thing I would encourage you to do is pick up a biography or autobiography of a missionary.  You would be surprised by the lives of some of the Christians who gave up everything to follow Christ. 

    What about ministering to others?  I believe that walking faithfully before God is walking in obedience to his commands (I Kings 2:3-4).  And what was Christ’s command?  Love one another (Matthew 37-39).  As we grow in faith and love towards God, it will result in walking (or acting) in a Christ-like way towards others.

-Mark