Usually in the context of the Bible, a mention of "Philip" brings the Apostle Philip to mind. He's the one who said to Jesus at the Last Supper, "Show us the Father and that will be enough for us" (!!), provoking from Jesus a slightly exasperated, "Have I been with you all this time and you still don't know me? Whoever sees me sees the Father!"
But that's not the Philip we read about in today's liturgy. This is "Philip the Evangelist," and from the way Luke writes about him in Acts, he seems to have been one of the most likable people in the whole Bible. We first encountered Philip in Acts 6, where he was one of the Greek-speaking members of the Jerusalem community chosen to administer the food pantry. Named right after Stephen, Philip was considered "of good reputation, filled with the Spirit and wisdom." Next, we see him in Samaria, preaching with great enthusiasm and winning a whole town to the gospel. And in today's first reading, he overhears the royal treasurer of Ethiopia reading the prophecies of Isaiah and offers him a Christological interpretation of the Suffering Servant passage.
That's not the last we see of Philip. Toward the end of Acts, we find him settled in Caesarea, where he gives hospitality to Paul, Luke and their entourage right before Paul's arrest in Jerusalem. Luke adds that Philip has four virgin daughters who are prophets. Clearly, Luke is not highlighting the women's marital status, which would be irrelevant to the Christian reader. Instead, this is the first evidence we have of Christian chastity being adopted as a lifestyle; the first witnesses of what we now call religious consecration.