Over three years had passed since his conversion to Christianity from Judaism. He had visited Arabia, Damascus, and finally the birthplace of the church – Jerusalem.
And when Saul had come to Jerusalem, he tried to join the disciples; but they were all afraid of him, and did not believe that he was a disciple. But Barnabas took him and brought him to the apostles. And he declared to them how he had seen the Lord on the road, and that He had spoken to him, and how he had preached boldly at Damascus in the name of Jesus. Acts 9:26-27
Your ability to defend the faith may start with your own testimony or the testimony of others about you. It is important for you to live an upstanding life in Christ in order to defend the faith and not defend yourself.
Paul was later accused of many things but it was all unfounded.
The Jews who had come down from Jerusalem stood about and laid many serious complaints against Paul, which they could not prove, Acts 25:7
Paul would also give you the instruction of righteous living, through his letter to the Colossians.
Be filled with the knowledge of His will in all wisdom and spiritual understanding; that you may walk worthy of the Lord, fully pleasing Him, being fruitful in every good work and increasing in the knowledge of God; Col 1:9-10
Your Christian apologetics will more fulfilling when you live according to the scripture and the Spirit.
Abba, I want to be filled with Your knowledge and wisdom. In Jesus name, YES&AMEN