Note 1 at Acts 9:26: This verse leaves the impression that Paul went immediately from Damascus to Jerusalem. However, in Gal. 1:15-18, Paul implies it was three years after his conversion before he went to Jerusalem and spent 15 days with the apostle Peter.

It is possible that during the "many days" of verse 23, Paul could have gone into Arabia and then have returned to Damascus, but the Jerusalem disciples' fear of him makes it look like Saul's appearance in Jerusalem was shortly after his conversion. If this would have taken place three years later, it seems that most Christians would have viewed his noticeable lack of persecution of the saints as proof enough that Saul's conversion was genuine.

It is possible that Galatians 1:18 and this account are describing two separate trips to Jerusalem. Saul could have come to Jerusalem immediately after leaving Damascus and then have returned three years later and spent 15 days with the apostle Peter. The statement in Galatians 1:17, "Neither went I up to Jerusalem to them which were apostles before me" is emphasizing the fact that Paul was not taught his revelation of the New Testament by any of the apostles. It does not rule out that he had been in Jerusalem since his conversion.

It is also possible that Paul spent three years between Damascus and Arabia then went to Jerusalem where he spent 15 days with Peter (Gal. 1:18).

Note 2 at Acts 9:26: The believers weren't sure that Saul had really been converted but thought this might be a trick so Saul could obtain names that would aid in his persecution of the saints. However, verse 27 shows that after Barnabas explained his actions at Damascus, they did receive him without restrictions. This showed a great faith on the saints' part.