In God´s holy word the bible you can find evidence that God´s Kingdom was not established in 1914. And according to the prophecies it will be estblished later in the future. And we can not calculate the time point. In Acts 1:7 the apostles asked " Lord, are you restoring the kingdom to Israel at this time?" And in the next verse he said to them: It does not belong to you to know times or appointed times which the Father has placed under his own authority. So, Jesus did not give any hope that we could calculate when God´s Kingdom will be established.
At the bookstudy we have also learnt about 3 woes, wich give more evidence that God´s kingdom is not yet established in heaven. We have learnt that we live in the time of the second woe, caused by the cavalry of two myriads of myriads. (Revelation 9:12-11:14) That is at the time when also the other sheep are spreading the kingdom message. This time period is quite long. This even causes a feeling of delay.( Revelation 10:6,7) The first woe brought locusts, wich symbolise anointed cristians in their symbolic 5 month preaching campain. But remark that according to the prophesy, the 3:rd woe comes with the establishement of the kingdom of God.( Revelation 11:14,15) After that the real catastrophy begins, the 3:rd woe. Satan will be hurled down to the earth.(Rev. chapter 12) That is, I believe the great tribulation before Armageddon.