This principle is beautifully demonstrated in the ministry of Philip the evangelist as recorded in the book of Acts. Philip had preached to receptive crowds in Samaria, but was later directed by an angel to journey to a specific road. There he was led to an incredibly receptive seeker:
But an angel of the Lord spoke to Philip saying, “Get up and go south to the road that descends from Jerusalem to Gaza.” (This is a desert road.) So he got up and went; and there was an Ethiopian eunuch, a court official of Candace, queen of the Ethiopians, who was in charge of all her treasure; and he had come to Jerusalem to worship, and he was returning and sitting in his chariot, and was reading the prophet Isaiah. Then the Spirit said to Philip, “Go up and join this chariot.” Philip ran up and heard him reading Isaiah the prophet, and said, “Do you understand what you are reading?” And he said, “Well, how could I, unless someone guides me?” And he invited Philip to come up and sit with him. Now the passage of Scripture which he was reading was this:
He was led as a sheep to slaughter; and as a lamb before its shearer is silent, so He does not open his mouth. In humiliation His judgment was taken away; who will relate His generation? For His life is removed from the earth.
The eunuch answered Philip and said, “Please tell me, of whom does the prophet say this? Of himself or of someone else?” Then Philip opened his mouth, and beginning from this Scripture he preached Jesus to him. As they went along the road they came to some water; and the eunuch said, “Look! Water! What prevents me from being baptized?” And Philip said, “If you believe with all your heart, you may.” And he answered and said, “I believe that Jesus Christ is the Son of God.” And he ordered the chariot to stop; and they both went down into the water, Philip as well as the eunuch, and he baptized him. When they came up out of the water, the Spirit of the Lord snatched Philip away; and the eunuch no longer saw him, but went on his way rejoicing (Acts. 8:26-39).
Philip was divinely directed to minister to a man who was so spiritually hungry that he had journeyed from Africa to Jerusalem to worship God and had purchased at least a portion of a copy of the scrolls of Isaiah’s prophecies. As he was reading the 53rd chapter of Isaiah, the most explicit scripture in the Old Testament that details the atoning sacrifice of Christ, and wondering whom Isaiah was writing about, there was Philip, ready to explain what he was reading! There was a man ripe for conversion! God knew his heart and sent Philip.