Looking at the exploits that God wrought through Philip in this chapter teaches me that sometimes God may allow some crises to as to equip and train His people. The persecution in Jerusalem that led to the scattering of the disciples brought out the Evangelist in Philip.
Also, in achieving this feat, Philip was very responsive to the Holy Spirit (v.26, 29) and he was always led to where there was a need. The conversion of Simon and the Eunuch were significant.
It therefore follows that depending on the Holy Spirit is the best channel to successful evangelism. Going where He bids us will yield great results despite whom we meet.