This....
Acts 9:19 And when he had received meat, he was strengthened. Then was Saul certain days with the disciples which were at Damascus. 9:20 And straightway he preached Christ in the synagogues, that he is the Son of God.
and this...
Galatians 1:15 But when it pleased God, who separated me from my mother's womb, and called me by his grace, 1:16 To reveal his Son in me, that I might preach him among the heathen; immediately I conferred not with flesh and blood: 1:17 Neither went I up to Jerusalem to them which were apostles before me; but I went into Arabia, and returned again unto Damascus.
...are this...
Acts 9:19 And when he had received meat, he was strengthened. [...went into Arabia, and returned again unto Damascus.] Then was Saul certain days with the disciples which were at Damascus.
9:20 And straightway he preached Christ in the synagogues, that he is the Son of God.
Meaning, he already had his instruction to preach Christ in him to the heathen; which now included Unbelieving Jews, and of course, Helenized Jews (Grecians).
Acts 9:29 And he spake boldly in the name of the Lord Jesus, and disputed against the Grecians: but they went about to slay him. 9:30 Which when the brethren knew, they brought him down to Caesarea, and sent him forth to Tarsus.
Where did he go?
Unto whom did he preach what?
Galatians 1:20 Now the things which I write unto you, behold, before God, I lie not. 1:21 Afterwards I came into the regions of Syria and Cilicia;
Cilicia - that is WHERE Tarsus is.
Acts 21:39 But Paul said, I am a man which am a Jew of Tarsus, a city in Cilicia, a citizen of no mean city: and, I beseech thee, suffer me to speak unto the people.
Who do we later read he had preached what to BACK IN ACTS 9?
Acts 15:23 And they wrote letters by them after this manner; The apostles and elders and brethren send greeting unto the brethren which are of the Gentiles in Antioch and Syria and Cilicia:
Acts 15:24 Forasmuch as we have heard, that certain which went out from us have troubled you with words, subverting your souls, saying, Ye must be circumcised, and keep the law: to whom we gave no such commandment: 15:25 It seemed good unto us, being assembled with one accord, to send chosen men unto you with our beloved Barnabas and Paul, 15:26 Men that have hazarded their lives for the name of our Lord Jesus Christ. 15:27 We have sent therefore Judas and Silas, who shall also tell you the same things by mouth. 15:28 For it seemed good to the Holy Ghost, and to us, to lay upon you no greater burden than these necessary things; 15:29 That ye abstain from meats offered to idols, and from blood, and from things strangled, and from fornication: from which if ye keep yourselves, ye shall do well. Fare ye well. 15:36 And some days after Paul said unto Barnabas, Let us go again and visit our brethren in every city where we have preached the word of the LORD, and see how they do. 15:40 And Paul chose Silas, and departed, being recommended by the brethren unto the grace of God. 15:41 And he went through Syria and Cilicia, confirming the churches.
What was said about his ministry among both those Jews and Gentiles he had preached unto?
Acts 21:17 And when we were come to Jerusalem, the brethren received us gladly. 21:18 And the day following Paul went in with us unto James; and all the elders were present. 21:19 And when he had saluted them, he declared particularly what things God had wrought among the Gentiles by his ministry. 21:20 And when they heard it, they glorified the Lord, and said unto him, Thou seest, brother, how many thousands of Jews there are which believe; and they are all zealous of the law: 21:21 And they are informed of thee, that thou teachest all the Jews which are among the Gentiles to forsake Moses, saying that they ought not to circumcise their children, neither to walk after the customs.
21:25 As touching the Gentiles which believe, we have written and concluded that they observe no such thing, save only that they keep themselves from things offered to idols, and from blood, and from strangled, and from fornication.
Was verse 21 true?
Romans 7:1 Know ye not, brethren, (for I speak to them that know the law,) how that the law hath dominion over a man as long as he liveth?
7:4 Wherefore, my brethren, ye also are become dead to the law by the body of Christ; that ye should be married to another, even to him who is raised from the dead, that we should bring forth fruit unto God. 7:5 For when we were in the flesh, the motions of sins, which were by the law, did work in our members to bring forth fruit unto death. 7:6 But now we are delivered from the law, that being dead wherein we were held; that we should serve in newness of spirit, and not in the oldness of the letter.