Before the Last Supper and the Crucifixion three of the gospels record Jesus telling the disciples about the destruction of the temple which happened in AD 70 and His Second Coming (Matthew 24, 25, Mark 13, Luke 21). This was intended to prepare the disciples for advancing His Kingdom. Earlier on Jesus chose His apostles (Matthew 10:2-4, Mark 3:13-19, Luke 6:12-16) after a very busy time healing the crowds that were pressing on Him. (Mk3:7-12) This was all in preparations for things to come. It shows we need to keep looking ahead for opportunities to advance His Kingdom and to prepare for them.
Now we of the Christian church need to continually prepare for the great Event of the return of Jesus to judge and restore. (Revelation 19). This doctrine tends to be a much neglected in the British church but it is mentioned frequently in the New Testament, eg Luke 12, 17, 1 Corinthians 15, 1 Thessalonians 4 – 2 Thessalonians 2, 2 Peter 3, Revelation 4-22 plus innumerable shorter references. Note that none of the references to Jesus’ return satisfy our curiosity as to the time and details, but what they do keep telling us is to be ready!
Mark13:33 Be on guard! Be alert! You do not know when that time will come.
Keeping this in mind should help us to sin less and prepare for the advancement of His Kingdom.