Matthew 3:17 says: And there a came a voice from Heaven, 'This is my my beloved Son. I take delight in Him.' Mark 1:11 says: And a voice came from heaven saying, 'You are my beloved Son; I take delight in you. Luke 7:22b: And a voice came from Heaven: 'You are my beloved Son. I take delight in you.' John 1:29 "The next day John saw Jesus coming toward him and said. 'Here is the Lamb of God who takes away the sin of the world.'
The account in Matthew indicates that the voice from Heaven seemed to be speaking to those who were watching the ceremony and pointed to Jesus by saying "This is my beloved Son." In Mark the voice from Heaven addresses Jesus directly and says "You are my beloved Son." Luke uses the same address Mark does. Most scholars agree that, even though there are differences, many details are copied from the same source.
John takes a different view than the other three. He is speaking to a group of his disciples and points Jesus out as "the Lamb of God that takes away the sin of the world."
All agree that this is the beginning of Jesus' ministry. Only John recognizes him as the Savior. The praise of the Father is assurance to Jesus that he is on the right path. Each of these introductions is significant for Jesus. I can only imagine the joy of knowing His Father's pleasure in him. It is John's announcement that challenges the Jewish leaders. They heard about John's statement and realized this was someone they could not ignore.