Timothy is a major player in this book. He was "on fire for the Lord", and Paul took him traveling with him to learn the model of ministry. He was eventually trusted with the great responsibility of fostering the church in Ephesus and the area around present day western Turkey.
Key Verse for these letters is 1 Timothy 3:15, Acts 16:1-3
Also :
Titus 3:12; Titus 1:5
Romans 15:24; Acts 20:29-31