A problem for interpretation and for harmonization involves the superficial contradiction between Acts 9 in which Paul moves about freely in Jerusalem, staying with the Apostles, speaking boldly in the name of the Lord, talking and debating with the Hellenistic, or Grecian Jews. Where as in Galatians 1 he writes, “I was personally unknown” to the churches of Judea that are in Christ they only heard the report of the man who formally persecuted us is now preaching the faith he once tried to destroy. On more careful inspection, the supposed contradiction dissolves.
Both Acts and Galatians allow for Paul to have met with some unspecified number of Apostles. In Galatians it is limited to Peter and James, the Lord’s brother. Moving about freely in Jerusalem hardly would have implied that Paul would have become well known to any other Christians there since that movement was still so tiny, but what Acts 9 emphasizes even more is that his ministry took place not among fellow Christian believers, but with the other Jews from the Diaspora like he was as he tries to share his faith with them just as he had done in Damascus three years earlier. He was personally unknown to most Christians, but not to many of his former Jewish compatriots.
This harmonization does more than simply preserve the non-contradictory nature of the Scripture's teaching, but reminds us of an important principle applicable in any time and culture mainly that young believers, young in spiritual age, often have one of their best windows of time and opportunities to evangelize their still unsaved family and friends because their experience is undeniable, their transformation can be seen, and they still have many contacts and acquaintances within the non-Christian world. Unfortunately, often times Christians become so re-socialized into the Christian community that within a couple of years they do not have nearly as many significant non-Christian acquaintances.