Dispensationalism simply means "administration." It refers to different ways that God administers His plan in history. But it is important to note, it is a man made theological construct in organizing and understanding God's work. This especially deals with Gods management of the family of God throughout Biblical history.
Traditionally, Dispensationalism divides the history of mankind into seven distinct dispensations, each has a purpose in the overall human drama of biblical history. The most commonly thought of is the dispensation of Law, and the dispensation of Grace. The purposes of our study here is limited to Law and Grace.
John Nelson Darby
Dispensationalism developed as a system from the teachings of John Nelson Darby, (1800-1882). Darby’s view of Isaiah 32 for instance required a future fulfillment and a realization of Israel’s kingdom. He saw the New Testament church in a separate program unrelated to that kingdom. Thus, there was a prophetic earthly kingdom program for Israel, and a separate “mystery” heavenly program for the church. To not conflate the two programs, the prophetic program must be put on hold to allow for the church to come into existence. Then the church must be raptured away before the prophecy can resume its earthly program for Israel.
Therefore, following the rapture (1 Thessalonians 4:13-18) , God will turn His attention on Israel and the Jewish people, thereby, finally restoring Israel to fulfill Isaiah 32. This view however destroys Romans 1:16 (To the Jew First), and places the responsibility for Jewish salvations solely upon God following a set of future events. If the door of salvation to the Jew has been closed until these events transpire, we cannot explain away the millions of Jews that have been getting saved since Messiah’s first advent. We acknowledge, there is a hardening in part that prevents all Israel from getting saved, but a remnant has always existed, a number that no one can count that remains open to the light of Messiah during this present age.
Dispensationalism has the
Full Number of the Gentiles Must Come In: Romans 11:25 -26, “ For I do not want you, brethren, to be uninformed of this mystery — so that you will not be wise in your own estimation — that a partial hardening has happened to Israel until the fullness of the Gentiles has come in; 26 and so all Israel will be saved; just as it is written “THE DELIVERER WILL COME FROM ZION,HE WILL REMOVE UNGODLINESS FROM JACOB.”“THIS IS MY COVENANT WITH THEM,WHEN I TAKE AWAY THEIR SINS.”
2.The Tribulation Must Occur, (Revelation chapters 6–19.) Believers who have been raised
together with living believers and transformed, are now caught up in the clouds to meet
the Lord in the air (I Thessalonians. 4:16-17). After this meeting in the air, the raptured
church continues to be with Christ as he completes his descent to earth. Further, the
raptured believers are judged for their works according to (Corinthians 5:10).
3.The Church Must Be Raptured: With the Church raptured, Israel now enters a final
preparation period through the trials of the Great Tribulation.The trials during this time,
are also called Jacob's Trouble Day of the Lord, ) . Out of this time of great wrath
Israel will be humbled through great suffering, and will finally acknowledge the one
whom they have pierced, and the second coming of the Messiah will commence when all
Israel will be saved.
Notably: The remnant of Israel who survive the tribulation will be saved, and the Lord
will establish His kingdom on this earth with Jerusalem as its capital. With Yeshua
reigning as King, Israel will be the leading nation, and representatives from all nations
will come to Jerusalem to honor and worship the King—Jesus Christ. The church will
return with Christ and will reign with Him for a literal thousand years (Revelation
 Isa. 2:12; 13:6,9; Ezek. 13:5; 30:3; Joel 1:15; 2:1, 11, 31; 3:14; Amos 5:18, 20; Zephaniah 1:7, 14; Zechariah. 14:1; and Malachi.4:5. Some of the passages that mention the Day of the Lord in the New Testament include Acts 2:20; 2 Thessalonians. 2:2; 2 Peter 3:10.
" For I am not ashamed of the gospel, because it is the power of God that brings salvation to everyone who believes: first to the Jew, then to the Gentile."