Since the Ascension Christ’s coming in glory has been imminent, even though “it is not for you to know times or seasons which the Father has fixed by his own authority.”. This eschatological coming could be accomplished at any moment, even if both it and the final trial that will precede it are “delayed”.
The glorious Messiah’s coming is suspended at every moment of history until his recognition by “all Israel”, for “a hardening has come upon part of Israel” in their “unbelief” toward Jesus. St. Peter says to the Jews of Jerusalem after Pentecost: “Repent therefore, and turn again, that your sins may be blotted out, that times of refreshing may come from the presence of the Lord, and that he may send the Christ appointed for you, Jesus, whom heaven must receive until the time for establishing all that God spoke by the mouth of his holy prophets from of old.” St. Paul echoes him: “For if their rejection means the reconciliation of the world, what will their acceptance mean but life from the dead?” The “full inclusion” of the Jews in the Messiah’s salvation, in the wake of “the full number of the Gentiles”, will enable the People of God to achieve “the measure of the stature of the fullness of Christ”, in which “God may be all in all”.
From the Catechism of the Catholic Church 673-674