Philip said, “If you believe with all your heart, you may.” He answered, “I believe that Jesus Christ is the Son of God.”
— Acts 8:37
As recorded in Acts 8, Philip was out in the desert and saw the Ethiopian eunuch in a chariot. The Holy Spirit said to him, “Go to this chariot and stay with it” (Acts 8:29). The eunuch was reading from Isaiah 53: “He was led as a sheep to slaughter; and as a lamb before its shearer is silent, so He opened not His mouth” (Acts 8:32). Philip asked him, “Do you understand what you are reading?” (v. 30).
Then the eunuch said to Philip, “I ask you, of whom does the prophet speak, of himself or of someone else?” (v. 34). Then we read: “Then Philip spoke, beginning with the same Scripture, and preached Jesus to him” (v. 35).
Beginning at that Scripture, Philip preached Jesus to him. So we see that the authoritative New Testament Scripture makes very clear that this passage is talking about Jesus Christ. Just the very content of it makes it absolutely plain—crystal clear, that that is what it is about.
This Ethiopian treasurer might have been the first person that we know of who was converted to Christ by the words of Isaiah 53, but millions have followed in his footsteps.