Acts 1:6-8 (KJV)

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

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

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.

Here the Lord shows us two things one of them we should not waste our efforts on and the other is the great commission which He will empower us to do by the Holy Spirit.
Only the Father knows when the Church will be raptured and when Jesus will return in His second coming. Matthew 24:36 (KJV) But of that day and hour knoweth no man, no, not the angels of heaven, but my Father only.
Therefore let us not speculate on something we will only know when it actually happens. 
Instead let us be filled with the Holy Spirit, encourage one another and together in unity 

Matthew 28:19-20 (KJV)

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 alway, even unto the end of the world. Amen.