Acts of the Apostles 16:1-3

Paul went first to Derbe and then to Lystra, where there was a young disciple named Timothy. His mother was a Jewish believer, but his father was a Greek. Timothy was well thought of by the believers in Lystra and Iconium, so Paul wanted him to join them on their journey. In deference to the Jews of the area, he arranged for Timothy to be circumcised before they left, for everyone knew that his father was a Greek.