The former treatise have I made, O Theophilus, of all that Jesus began both to do and teach, Until the day in which he was taken up, after that he through the Holy Ghost had given commandments unto the apostles whom he had chosen: To whom also he shewed himself alive after his passion by many infallible proofs, being seen of them forty days, and speaking of the things pertaining to the kingdom of God: And, being assembled together with them, commanded them that they should not depart from Jerusalem, but wait for the promise of the Father, which, saith he, ye have heard of me. For John truly baptized with water; but ye shall be baptized with the Holy Ghost not many days hence.
Acts 1:1-5
It is very important that we truly grasp Christ’s mission and message. He began by preaching: Repent, for the Kingdom of Heaven is at hand. Then He went about all Galilee preaching the gospel of the Kingdom of God. And then He sent the disciples to go and preach the gospel of the Kingdom of God. He declared that Him casting out devils by the Spirit of God means that the Kingdom of God is made manifest. Then after His resurrection, in the final moments before He departed to Heaven, His stress was on the Kingdom of God. He came a King, He died a King, he rose a King and He is coming back to earth as the King of kings and the Lord of lords.