A little background for our new journey:

1 Timothy was written by the Apostle Paul to Timothy sometime after his release from Roman imprisonment as described at the end of the Book of Acts and was written from Macedonia

Apparently, after his release, Paul returned to the city of Ephesus. There he discovered that during his absence Ephesus had become a storm center of false teaching.

Paul probably dealt with the false teachers personally, but soon found it necessary to leave for Macedonia. He then left Timothy in charge of affairs at Ephesus, as his own personal representative. He knew that Timothy had a difficult job to carry out, so he hoped that this letter would both equip and encourage him in the task.

1 Timothy 1
Paul, an apostle of Jesus Christ, by the commandment of God our Savior and the Lord Jesus Christ, our hope,
2 To Timothy, a true son in the faith:
Grace, mercy, and peace from God our Father and Jesus Christ our Lord.

Paul could consider Timothy a true son in the faith because he probably led him and his mother to faith in Jesus on Paul’s first missionary journey (Acts 14:8-20 and 16:1). This also expressed Paul’s confidence in Timothy’s integrity and faithfulness to the truth.