When the disciples asked about the timing of the Kingdom, Jesus let them know that they were concerned about the wrong thing. What they needed was to receive power. They needed the power of the Holy Ghost coming upon them. They needed the baptism of the Holy Spirit, and so do we. They needed this power to be a witness, and so do we.

Acts 1:4 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.

Acts 1:5 For John truly baptized with water; but ye shall be baptized with the Holy Ghost not many days hence.

Acts 1:6 When they therefore were come together, they asked of him, saying, Lord, wilt thou at this time restore again the kingdom to Israel?

Acts 1:7 And he said to them, It is not for you to know the times or the seasons, which the Father hath put in his own power.

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 Judea, and in Samaria, and unto the uttermost part of the earth.