In his letter to the Roman Church Paul emphasizes "Faith", not behavior, as the key to claiming the gift of Salvation.
We all fall short of God's glory. ALL; not some; not some more than others… We ALL all short-period.
The early Church took the message of Jesus the streets so that the world would know the Good News.
Saul (Paul) was transformed from a Christian killer into a Christian killed, as a leader of the early Church.
There was quite a change from Peter Pre-Pentecost to Peter Post-Pentecost !