Mt 28:18-20, Mk 16:15, Acts 1:8, Jer 3:15
In the Old Testament, it was foretold that God would send a shepherd to feed the sheep with knowledge and understanding. (Jer 3:15)
Jer 3:15 And I will give you pastors according to mine heart, which shall feed you with knowledge and understanding.
The resurrected Jesus told Peter to feed the sheep. This is to teach that Jesus is the Christ. (Jn 21:15-17)
Jn 21:15 So when they had dined, Jesus saith to Simon Peter, Simon, son of Jonas, lovest thou me more than these? He saith unto him, Yea, Lord; thou knowest that I love thee. He saith unto him, Feed my lambs. 16 He saith to him again the second time, Simon, son of Jonas, lovest thou me? He saith unto him, Yea, Lord; thou knowest that I love thee. He saith unto him, Feed my sheep. 17 He saith unto him the third time, Simon, son of Jonas, lovest thou me? Peter was grieved because he said unto him the third time, Lovest thou me? And he said unto him, Lord, thou knowest all things; thou knowest that I love thee. Jesus saith unto him, Feed my sheep.
And the resurrected Jesus told us to preach that Jesus is the Christ throughout the world. (Mt 28:18-20, Mk 16:15, Acts 1:8)
Mt 28:18 And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth. 19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: 20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world. Amen.
Mk 16:15 And he said unto them, Go ye into all the world, and preach the gospel to every creature.
Acts 1:8 But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth.