"This is a personal letter to Timothy, son of a Greek father and a Jewish mother. He was converted during Paul's visit, to Lystra (Acts 16.1). He became Paul's special protégé, and, though evidently diffident and nervous in temperament, was his loyal assistant. He accompanied Paul on various missions and has now been left in charge of the church at Ephesus". 

- From the introduction.

Originally published in Letters to Young Churches.