In a frequently repeated statement, Ernst Käsemann famously said that “Apocalyptic was the mother of all Christian theology.” Not as well-known is that two years later, Käsemann clarified what he actually meant by “apocalyptic”: for him, it referred to “eschatology,” or in his words, “the expectation of an imminent Parousia.” Personally, I would define apocalyptic eschatology a bit more broadly. Apocalyptic eschatology is the belief that this present age is irredeemably corrupted by sin, that God is coming to intervene in a final judgment on the wicked, and that at that time he will vindicate the righteous and deliver them into a new of age of eschatological salvation that is both personal in the sense of resurrection and cosmic in the sense of renewal. The question remains, however, as to how this perspective might rightly be considered to be the “mother of all Christian theology,” and in the space that remains, I would simply like to offer a few brief explanations for this claim.

First, apocalyptic eschatology revolves around the final, climactic visitation of God to the earth. In the Old Testament, this visitation was often referred to as “the Day of the Lord.” In fact, there were many “days of the Lord” in the Old Testament, all of which function as typological portends of the final Day of the Lord when God comes in eschatological glory and power. Christian theology believes that this final Day of the Lord began when God came to earth in the incarnate Lord Jesus Christ. He was to be called Emmanuel, which is translated “God with us.” (Matthew 1.23). And the Lord Jesus himself said of Jerusalem, “you did not recognize the time when God visited you.” (Luke 19.44) This is exactly the point, namely that the coming of Christ in his incarnation was the beginning of the apocalyptic visitation of God to the earth. Of course, we know that He is coming again in glory and power to bring to consummation that which he began in His first coming, but the point here is that in Christ, God himself came in climactic apocalyptic visitation.

And this brings me to the second reason why apocalyptic eschatology is the mother of all Christian theology, namely that the first coming of Christ to the earth as a baby in a manger marked the beginning of the end of this corrupt present age. In New Testament theology, this is commonly referred to as the already and the not yet, namely that God’s plan for the final redemption of his people has already begun in Christ but it is not yet complete. Consequently, we live in this in between time of already and not yet, already saved, already filled with the eschatological spirit, already living under the blessings of God’s eschatological salvation in part, but we await the time when Christ will come again to consummate, or to bring to completion, that which he began by his death, resurrection and ascension. This is why Peter, in his Pentecost sermon, can say, “And it will be in the last days, says God, that I will pour out my Spirit on all people.” (Acts 2.17). The underlined phrase marks a change that Peter has applied to his source text (Joel 2.28), which simply says, “After this.” Peter understood that in Christ the last days had begun, and we have been living “in the [apocalyptic] last days” now for 2000 years.

But what about the final judgment of the wicked? Isn’t this something that is still yet future? How can we say that the apocalyptic judgment of the wicked began in Christ at his first coming? The answer is that this is exactly what we must say, as Jesus says in John 12.31-32, “Now is the judgment of this world. Now the ruler of this world will be cast out. As for me, if I am lifted up from the earth I will draw all people to myself.” The verb here, “lift up”, means to lift up on high, to exalt, or to raise to dignity and honor. This is why it is so ironic that John goes on to add the explanatory note, “He said this to indicate what kind of death he was about to die.” (John 12.33) The death of Jesus on the cross is nothing less than his enthronement. By his death, he judges the wickedness of this world and its ruler; He exposes the sinfulness and the ultimate fate of those that would reject him. This is why we can say that the final judgment began in Jesus, because a person’s response to the crucified and risen Christ will determine their eternal fate. In the death of Christ, judgment has begun, and it will be meted out when “the lamb who was slain,” as the Revelation calls him, returns in glory and power.

Finally, apocalyptic eschatology is the mother of all Christian theology because in Christ eschatological salvation has come. Salvation is inherently and irreducibly an eschatological concept. Saved from what, we might ask? We are saved from the eschatological wrath of God toward sin. And in Christ this salvation has broken into this present age and been made available to all those who respond to Christ in faith. This is why Peter refers to Joel’s prophecy to explain the coming of the Spirit at Pentecost, as we saw above. We have been filled with the eschatological Spirit, the seal and sign of the new age. We are new creatures, the fruit of a new creation, in Christ because of the Spirit. This is why the Apostle Paul can say, “Blessed is the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavens in Christ.” (Ephesians 1.3) Every spiritual blessing, every blessing of the age to come is already ours in Christ. We have been saved. We are being saved. And we will be saved. Apocalyptic salvation has already begun in Christ, and we are partakers of it by His indwelling Spirit.

So, I agree with the sentiments of Ernst Käsemann as expressed above. Apocalyptic eschatology is the mother of all Christian theology, because in Christ the apocalyptic visitation of God has come. All of the rest of our theology must be derived from this point, that the climactic work of God for the salvation of His people and His world has come in Christ. This is the Gospel; this is the good news of our salvation. In Christ, God himself has broken into this present age to redeem his people from their sin and set us free from its bondage, its corruption, even its very presence. And this is why we can have hope.