Paul found Timothy on his second missionary journey when he arrived in Lystra. Timothy was a young convert, however, nothing is said in the scriptures about the when or where of his conversion. We know that he was already a Christian when Paul found him (Acts 16:1-2). His mother Eunice, and his grandmother Lois had a large part in his religious education (2 Tim. 1:5; 3:14-15). His mother was Jewish, married to a Gentile. This provided for an interesting obstacle to his labor among the Jews in that he had not been circumcised. Paul quickly took care of that problem (Acts 16:3) and took Timothy with him on the remainder of his journeys.

We know not exactly the circumstance of Paul adopting Timothy as his assistant, but according to Paul, knowledge of Timothy was revealed from God through prophecy (1 Tim 1:18; 4:14). He was set apart to the work of an evangelist by the laying on of the elder hands (4:14), and encouraged in the work by Paul (2 Tim. 4:5; 2:2).

Timothy was a companion of Paul from Lystra through the rest of his journeys. It was not long after they departed Lystra that Paul saw fit to leave Timothy at Philippi, then at Ephesus. He was entrusted with the welfare of that church, given the duty to defend the faith against all who would teach error, set in order the workings and organization of the church, and put the brethren in mind of the things that were taught by Paul. It is believed by many that at one time Timothy shared Paul’s imprisonment, but was released (Heb. 13:23). Of that we cannot be altogether certain, and what happened to Timothy after the death of Paul there is nothing but legend.

Paul’s affection for Timothy as a surrogate son is seen in this appellation, "my true child in the faith" (1 Tim. 1:2), and in his pleading with Timothy to come before his time was up (2 Tim. 4:9-12, 21).