New Defender's Study Bible Notes
16:16 Thou art the Christ. Peter’s great confession apparently was given as spokesman for all the disciples since Jesus had asked them the question (Matthew 16:15). They understood that Jesus was both the promised Messiah (i.e., “the Christ”) and also the only begotten Son of God. They had learned this first of all from John the Baptist (see John’s testimony as recorded in John 1:15-18), but this had been further confirmed by their personal knowledge of Christ and by the inward witness of the Holy Spirit.