"But when God, who set me apart from birth and called me by his grace, was pleased to reveal his Son in me so that I might preach him among the Gentiles, I did not consult any man," NIV translation
When Jesus showed up and changed Paul from a murderer to an evangelist, he did not go check with anyone to get permission. He understood that he had been set aside even before his birth for this purpose and he simply embraced what God would have him to do. That is the same for us as we all have been saved for a purpose and that purpose was set even before we were born. If we listen to God and not the words of men, He will tell us what He has designed for us to do. We can also be sure that it is better than anything we could come up with on our own.
Paul goes on to explain that he didn't even have to check in with religious leaders because he already had his instructions from God. He first went into what is now Saudi Arabia but we do not know much about what he did there. We can only guess that God was preparing him for his upcoming missionary journeys.
"Then after three years, I went up to Jerusalem to get acquainted with Peter and stayed with him fifteen days. I saw none of the other apostles - only James, the Lord's brother. I assure you before God that what I am writing you is no lie." NIV translation
Paul goes on to explain that, even when he went to Jerusalem, he did not go there for approval or permission from them. There are many that forget that Jesus Christ is the head of the church and not a man but Paul never forgot that important fact. He went to Jerusalem to get to know Peter as he was known as a leader in the faith.
"Later I went to Syria and Cilicia. I was personally unknown to the churches of Judea that are in Christ." NIV translation
Paul lets us know that he went out to do what God had called him to do without even being known by the churches in Judea. This is a sharp contrast to what he did before as then he had authorization from the Jewish leaders to hunt down Christians. Now, we see that he has the very authority of God to call Gentiles to be saved and did not seek any other approval.
"They only heard the report: 'The man who formerly persecuted us is now preaching the faith he once tried to destroy.' And they praised God because of me." NIV translation
When Paul went on his travels spreading the gospel, people heard the news that he had been changed. They praised God as they could see the very power of God at work to change this man. We, too, should cause people to praise God because of the change that they see in us through that same power.