Jesus asked His disciples who they thought He was. He had certainly given them plenty of evidence to believe He was the Messiah. The miracles, healing, and His power over nature added supernatural confirmation to the “Good News” message Jesus was preachings to the crowds. Still, it must have been difficult even for the disciples to declare that their new leader, Jesus, was in fact the Messiah they had heard about all their lives.
Peter was impulsive in both his behavior and speech. So, while his fellow disciples answered Jesus’ question cautiously and diplomatically, Peter boldly acknowledged what he felt in his heart. He wasn’t constrained by what others thought or by their reaction to his declaration. Peter declared Jesus to be the Messiah because God had given him that truth and had opened his mouth to confess it.
MARK 8:29- And he saith unto them, But whom say ye that I am? And Peter answereth and said unto him, Thou art the Christ.