Galatians 1:19-24
Gal 1:19 (KJB)
But other of the apostles saw I none, save James the Lord's brother.
Save - Except
While Paul was in Jerusalem he had also met James who was the Lordís half brother. They had the same mother but Joseph was not the father of Jesus as He was conceived by the Holy Spirit. (Luke 2:33 KJV) And Joseph and his mother marvelled at those things which were spoken of him. Luke 2:33 does not refer to Joseph as His father.
Gal 1:20 (KJB)
Now the things which I write unto you, behold, before God, I lie not.
Lie - Deceive
Paul give his affirmation that everything which he is writing unto the Galatians is all the truth and there are no deceptions within those writings. He was not just giving an affirmation but Paul invoked the name of God, that God knows what Paul is writing is total truth.
Gal 1:21 (KJB)
Afterwards I came into the regions of Syria and Cilicia;
After Paul left Jerusalem he went through the regions of Syria and Cilicia. This would have been about a 100 mile trek north from Jerusalem. (Acts 15:40-41 KJV) And Paul chose Silas, and departed, being recommended by the brethren unto the grace of God. {41} And he went through Syria and Cilicia, confirming the churches. The Acts passage was from Paulís second missionary journey when he and Silas went through the Syria and Cilicia strengthening the churches.
Gal 1:22 (KJB)
And was unknown by face unto the churches of Judaea which were in Christ:
As Paul begins to wind down this part of the letter, he states that the people in the area outside of Jerusalem would not have known him. Paul would have been well known in Jerusalem but those churches outside of Jerusalem would not have known him, especially by face, but maybe he might have been known by reputation.
Gal 1:23 (KJB)
But they had heard only, That he which persecuted us in times past now preacheth the faith which once he destroyed.
Heard - Hearing with understanding
All that the churches on the outside of Jerusalem knew about Paul was how he had persecuted the church and attempted to arrest every Christian he could. They understood how he hated the church and wanted to destroy it. Now they understand that this same Paul who was a destroyer of the faith is now one who proclaims the very faith he loathed.
Gal 1:24 (KJB)
And they glorified God in me.
Here is the result of the churches seeing that God saved the biggest gospel hater of their time. God gets the glory for saving even the most vile and hating person. They knew that Paul was a church persecutor but now Paul was proclaiming the true Gospel and this brought glory to God among the Christians of the outer regions outside Jerusalem.