Acts 8:36-38 (NKJV)
36 Now as they went down the road, they came to some water. And the eunuch said, "See, here is water. What hinders me from being baptized?"
37 Then 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."
38 So he commanded the chariot to stand still. And both Philip and the eunuch went down into the water, and he baptized him.