Timothy was a convert to Christianity, a product of a mixed marriage between a Jewish mother and a pagan Greek father, and a Christian of some note in Lystra by the time of Paul’s second visit to that city. Timothy would have heard Paul’s preaching that afflictions would be necessarry to enter the kingdom of God. In addition to the basic rules that Gentile Christians must follow, the prohibition on eating meat with blood, the prohibition on sexual immorality, and the prohibition on food sacrificed to idols, Timothy was circumcised to avoid a distracting confrontation with the Judaizers in the Church. Timothy was quite influential as Paul’s envoy in Macedonia.
Titus was an early convert from a pagan background who went up to Jerusalem with Paul (possibly from Antioch). This background comes largely from the second chapter of Galatians.