Matthew Chapter 28, verses 18-20 King James Version

And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth. Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.

These verses are known as The Great Commission. They were the final instructions Jesus gave before He returned to Heaven, following His resurrection.