This letter was written by the Apostle Paul, while in prison in Rome. This was Paul’s second imprisonment. He was released from his first imprisonment, where he was under house arrest (Acts 28:30). Tradition holds that at the time of writing this, his last epistle, Paul was in Mamertine Prison, which was a “death row” prison. It is clear from the letter’s contents that Paul expects to be executed.
His purpose in writing this letter to his primary disciple Timothy was to bolster Timothy’s courage, and provide him with all the reasons why he too ought to embrace living life as a faithful witness who does not fear death, loss, or rejection. By application, Paul’s letter applies to any believer who desires to gain the most from their time on earth.