2:28-32 The promise began to be fulfilled on the day of Pentecost, when the Holy Spirit was poured out, and it was continued in the converting grace and miraculous gifts conferred on both Jews and Gentiles. The judgments of God upon a sinful world, only go before the judgment of the world in the last day. Calling on God supposes knowledge of him, faith in him, desire toward him, dependence on him, and, as evidence of the sincerity of all this, conscientious obedience to him. Those only shall be delivered in the great day, who are now effectually called from sin to God, from self to Christ, from things below to things above.
30, 31. As Messiah's manifestation is full of joy to believers, so it has an aspect of wrath to unbelievers, which is represented here. Thus when the Jews received Him not in His coming of grace, He came in judgment on Jerusalem. Physical prodigies, massacres, and conflagrations preceded its destruction [Josephus, Wars of the Jews]. To these the language here may allude; but the figures chiefly symbolize political revolutions and changes in the ruling powers of the world, prognosticated by previous disasters (Am 8:9; Mt 24:29; Lu 21:25-27), and convulsions such as preceded the overthrow of the Jewish polity. Such shall probably occur in a more appalling degree before the final destruction of the ungodly world ("the great and terrible day of Jehovah," compare Mal 4:5), of which Jerusalem's overthrow is the type and earnest.