"Gal 3:26 For ye are all the children of God by faith in Christ Jesus.
Gal 3:27 For as many of you as have been baptized into Christ have put on Christ.
Gal 3:28 There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
Gal 3:29 And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise. "
These verses of Galatians 3 are close to the doctrine in Galatians 3 which is very important to the foundation of the theology of Christian Zionism. This foundation of Christian Zionism asserts that God still honors the physical bloodline from Abraham through Isaac and Jacob.
Christian Zionists can, and so sometimes do, drop their belief in the pre-trib rapture,but remain Christian Zionists. The pre-trib rapture is not the foundation of their theology. The supposed continuation of the physical bloodline is that foundation.
Bring in Galatians 3: 3,16-17 and be sure to include Galatians 3: 26-29.
"Are ye so unwise that after ye have begun in the Spirit ye would now end in the flesh?.........To Abraham and his seed were the promises made. He sayth not in the seeds as in many: but in thy seed as in one which is Christ.
17 This I say that the law which began afterward beyond .iiii.C and .xxx.(four hundred and thirty) years doth not disannul the testament that was confirmed before of God unto Christ ward to make the promise of none effect.........For ye are all the sons of God by ye faith which is in Christ Jesus.
27 For all ye that are baptised have put on Christ.
28 Now is there no Jew nether Gentile: there is nether bond nor free: there is nether man nor woman: but ye are all one thing in Christ Jesus.
29 If ye be Christ's then are ye Abraham's seed and heirs by promise." Galatians 3: 3, 16-17. 26-29 Tyndale New Testament
Galatians 3: 3, 16-17, 26-29 is a little bit subtle, since it does not say the in an explicit statement that the physical bloodline was done away with. But the conclusion from what is said is that there is no more physical bloodline determining who is the chosen of God, the elect of God.
Yet one of the three main founders of dispensationalism, Lewis S. Chafer, says that "The nation Israel, God's chosen earthly people, to whom at least five-sixths of the Bible is addressed and with whom the great covenants are made (Rom 9:4-5) -- which covenants secure to that nation a land, a nation, a throne, a King, and a kingdom -- are now scattered throughout all the nations of the earth (Deut 4:26-28; Deut 28:63-68; Jer 16:13), and are to remain scattered until they (a remnant; ed.) are gathered into their own land (Deut 30:3-6; Isa 11:11-12; Isa 14:1-3; Isa 60:1-22; Jer 23:6-8; Jer 32:37-44; Jer 33:7-9; Eze 37:21-25; Mic 4:6-8) under the reign of Christ Jesus at His return."
Source for the above quote by Chafer:
http://anothervoicerev184.blogspot.com/p/lewis-sperry-chafer-return-of-jesus.html
The quote is down the page a bit to: II. THE COMING OF CHRIST PRODUCES FAR-REACHING EFFECTS:
"Return of Jesus Christ, The Rapture of the Church and the Second Coming of the Lord Jesus Christ, By Lewis Sperry Chafer 1871-1952."
In original dispensationalism the chosen people were chosen because of their physical bloodline, and so belief that the physical bloodline still determines who is chosen is now held by those who follow dispensationalism-Christian Zionism. Because the word dispensationalism does not describe well the doctrines of this theology, Stephen Sizer titled his 2006 book, "Christian Zionism: Road-map to Armageddon?" Christian Zionism is also a better term for the theology which says that the nation called Israel in the Middle East is really Israel in our time.