Paul the Precedent of Salvation
1Tim 1:16 However, for this reason I obtained mercy, that in me first Jesus Christ might show all longsuffering, as a pattern to those who are going to believe on Him for everlasting life.
For what reason did God show mercy to Paul and then make him the spokesman for the gospel to the Gentiles? One reason is so that it might be understood that salvation is available to everyone no matter how sinful their background.
What if a person hears the gospel and not only rejects it but then goes on a rampage persecuting Christians even with violence - making that their objective in life. Will God be long-suffering with such a person and if he repents forgive him? Paul's conversion is a pattern for such people. But indeed don't many of us fall into that category to a lesser extent. We're we all resistant, but over the long term God drew us to himself despite our resistance?
But for those who take God's longsuffering for granted, beware. "Do you despise the riches of His goodness, forbearance, and longsuffering, not knowing that the goodness of God leads you to repentance? But in accordance with your hardness and your impenitent heart you are treasuring up for yourself wrath in the day of wrath and revelation of the righteous judgment of God." Rom 2:4,5
Paul's conversion is also the pattern for those who would come to believe in that it shows what one should expect of believers - it shows the kind of repentance and changed life characteristic of salvation, characteristic of saving faith and regeneration.