Belief in Christ's Sonship to God needed preaching and interpretation. This appears explicitly in the incident of the Ethiopian eunuch who was met by Philip while reading Isaiah's prophesy about Christ. He could not understand the meaning of what he was reading, so Philip explained the chapter to him and preached Christ to him. The Ethiopian eunuch asked Philip to baptize him and Philip replied: " 'If you believe with all your heart, you may.' And he answered and said, "I believe that Jesus Christ is the Son of God " (Acts 8:2737). Common sonship does not need any explanation or interpretation or preaching because it is common to all.