1:24 And they glorified God because of me.
The Holy Bible: English Standard Version. 2001
Those who heard and witnessed the change in Paul recognized the source of change as being God on high. This recognition could have come through conversation with Paul, first hand observations of Paul, or rumored news of Paul.
The significance of this verse is that it the church was praising God and advancing His name. This example of the New Testament church serves as a standard for the modern day church to follow. It is our mission to make the name of Christ known and Great! John 12:32 reminds us that God will do the work of drawing men if we will remain committed to lift Him up!