“All authority in heaven and on earth has been given to me” (Matt. 28:18). 

I believe Jesus is simply saying that he has been entrusted with judging the living and the dead on the last day (cf. John 5:22–27; Acts 10:42; 2 Tim. 4:1). Until that day, his followers are called to disciple the Gentiles into the Jewish narrative (Matt. 28:19a), warning them of the impending day of judgment and baptizing them as a confirmation of their forgiveness and salvation from the wrath to come (Matt. 28:19b). The complete lack of reference to the day of the Lord in modern commentaries concerning Matt. 28:18 is simply astonishing... Such is the product of realized eschatology. -John P. Harrigan, The Gospel of Christ Crucified, p.319