In respect of the performing of miracles, my understanding has always been that this was a specific gift provided to the early apostles as a means of establishing the early church. Seemed to work, too.
What was your understanding of these passages back when you were a Christian apologist?
When I was a christian I would have pretended like any little thing I did was "greater miracles" than Jesus performed. Since then I have realized that I was just believing what I wanted to believe. Also, as a christian I can honestly say I wasnt nearly as well versed as I am now because in church functions they had us read the verses they wanted us to read, over and over, year after year. Never quite got to the ugly stuff many of us object to here.
The church spread thanks to Constantine, not the disciples.