Acts 8:30-31 Then Philip ran up to the chariot and heard the man reading Isaiah the prophet. "Do you understand what you are reading?" Philip asked. "How can I," he said, "unless someone explains it to me?" So he invited Philip to come up and sit with him.
 
When the Holy Spirit led Philip down to the desert road, Philip didn't know what God intended, but he obediently followed God's leading. The Lord revealed His will each step of the way. God showed Philip that he was to run along side a chariot and he did so. Then it became clear that he was to speak with the man  in the chariot and Philip did so. Philip obeyed God's leading one step at a time, quite literally. Here was a man who knew not Jesus but had a open heart to know Him. Fortunately for him, God led Philip, a man who when God says go south to the desert road, Philip takes off.
 
The world is full of people  who don't understand what they're reading. God's looking for a few faithful folks that He can send to explain it to them.
 
Sam