What was different about salvation on the day of Pentecost compared with John the Baptist's ministry?
On Pentecost, the message continued from John’s ministry, but the finished work of the cross had now been consummated, so God could save people on the basis of the shed blood. John baptized repentant believers before that completion, forming a separated group of Jews. Pentecost added about three thousand, though they did not yet believe the Gospel Paul later defines.
Les teaches that John the Baptist baptized as soon as people repented, and those believers became a separated group of Jews even then. At Pentecost, the same message was being furthered, but now the finished work of the cross had been consummated so God could save these people based on the shed blood. However, nothing yet indicates they were believing what we call the Gospel—First Corinthians 15:1–4, where Paul says Christ died for our sins according to the Scriptures. Instead, the message was 'you killed Him.' Les points to that as a total difference. The three thousand were added to this group of believers and continued steadfastly in the apostles’ doctrine—the twelve—who knew not much more than that Christ had come and fulfilled all the Old Testament promises.