Eschatology is a major theme permeating scripture, particularly Jesus’ teachings. The content of Jesus’ message was not only a future coming and a future kingdom; rather, with the advent of Jesus the kingdom of God had already arrived and will be consummated at the second coming.
Although, in the Old Testament, the day of the Lord is viewed as a future matter, in the New Testament it is depicted as a present occurrence that will be fully realized during the final return of Jesus. This concept has become a definite historical reality. Eschatology has been fulfilled or realized. Instead of looking ahead for future fulfillment of prophecy, we should note the ways in which it has already been fulfilled. Eternal life is already our possession (1 Jn. 2:25). Indeed the kingdom and the consummation of Christ's reign has begun and we are in the midst of the age to come and at the same time in the midst of the present age.