"When [Saul] came to Jerusalem, he tried to join the disciples, but they were
all afraid of him, not believing that he really was a disciple." (Acts 9:26 HCSB)
After his conversion experience, Saul had his vision restored through Ananias and then he was baptized. He started proclaiming the gospel in Damascus; the same place he came to arrest Christians and take them back to Jerusalem as prisoners. He did return to Jerusalem but not in the way he originally intended.
The people of Damascus were perplexed. "All those who heard him were astonished and asked, 'Isn’t he the man who raised havoc in Jerusalem among those who call on this name? And hasn’t he come here to take them as prisoners to the chief priests?'" (Acts 9:21)
We all know those people. Some of us might be those people: The ones who can never change, lifelong miscreants that took depravity to ever sinking levels and now we claim to be servants of God. Paul was more than a miscreant. He was a conspirator to murder and an outspoken critic of those who claimed Jesus as Messiah.
One can only speculate what some people thought. The believers didn't trust him. His supporters might have thought this was a ploy to get closer to members of the Way so he could trap more of them and gain evidence against them. But eventually those who despised Christians realized his conversion was real and they sought to kill him. The local believers helped him escape and he returned to Jerusalem, not with his bounty of arrested believers but with the power of the Holy Spirit and the message of eternal life. His arrival in Jerusalem was met with disbelief and distrust by the believers but Barnabas, a known disciple, vouched for Paul. Paul began preaching and debating with Greek speaking Jews and once again, he had to flee because his life was being threatened.
A bad reputation is hard to overcome and a good reputation is destroyed in a moment. Paul had a hard time overcoming the distrust of the believers but no problem making enemies of his former colleagues.
It's easy to get frustrated when we walk with the Lord; trying to overcome our past and convincing people we really have changed. Well meaning friends might even remind us of some of our past, not always in a mean-spirited way but as reminder of the good-ole' days. Perhaps it's better if we let our actions prove the change and not just our words.
Paul was able to overcome his bad reputation with the help of believers who were willing to extend him a hand of fellowship and vouch for him among the other believers. He also overcame that bad reputation through persistence in living the Christian faith and serving the Lord. He did not go back to his old ways, a familiar life and a comfortable life. He endured and became one of the true heroes of the Christian faith, a sinner saved by grace, a recipient of God's mercy, and a powerful tool in the hand of a mighty God.
We must all follow Paul's example. We can be changed through sanctification and we can be used to do great things for God. We must be persistent in walking with the Lord and serving him. We must guard our ways lest we fall and give our critics, God's critics, the ability to say, "See, I knew he'd never change."