Matt. 24:14 Gospel preached in all the world ...Colossians was penned about AD 63 -- Col. 1:23; Rom. 11:25; Rom. 1:8 ; Rom. 10:18; This was to be done before the "end" Jesus was telling Peter, James, John and Andrew about, Matt. 24:3.
Witness -- that Jesus' testimony is sure, accurate, his prophecy fulfilled. Luke 21: 13. The destruction of the temple to be a testimony that God's apostles were right in their preaching. XXX