While He was on earth Jesus did not need introduction. Everybody knew Jesus before He spoke. His actions, speeches, demeanour and everything about Him pointed to a clear fact that, that was a child of God. Many today who profess to be Christians are Christians by name but not in word and in deed.
The purpose of any teaching or instruction from the Bible is not just to provide us with the information but to seek and to build our character (1 Timothy 1:5). We need to begin to build our character from what we hear from the word of God.