After 2 years of house arrest in Rome (Acts 28:30) Paul embarked on another missionary journey. However, he found Timothy unwell with stomach problems and frequently ill, and seemingly not as enthusiastic for his faith as he once was.
This letter is a loving letter, encouraging Timothy and warning him of false teachers. Paul also gives him advice about a wide range of topics including worship, the appointment of leaders, money and right relationships between people. As such there is much in this letter so relevant to 21st century Christians.