A quick review will be helpful. Remember, that during Paul's time he argued against those who promoted the idea that Gentiles must convert to Judaism and live Jewishly in order to be saved. In that context, he argued that circumcision of the flesh is of some value, but what ultimately matters is circumcision of the heart.
Where did Paul get the idea of a circumcised heart?
Deuteronomy 30:5-6
The Lord your God will bring you into the land which your fathers possessed, and you shall possess it; and He will prosper you and multiply you more than your fathers. Moreover the Lord your God will circumcise your heart and the heart of your descendants, to love the Lord your God with all your heart and with all your soul, so that you may live. 7 The Lord your God will inflict all these curses on your enemies and on those who hate you, who persecuted you.
The Jews are NOT saved because they are Jews. The Jews are NOT saved because they have returned to the Land. According to verse 5, God will bring them back into the Land, which he is doing right now. And after the Jewish Aliyah, he will circumcise their hearts. In other words, they are saved because God will choose to save them, which will involve giving them a circumcised heart.
Selectively quoting Scriptures without including more context is why those professing to be Christian Zionists can make the Bible say anything they choose. Every promise regarding physical land of Cannan was fulfilled exactly as God promised, the twelve tribes from Jacob inherited the land. But what you don't include with your selective Bible reading is how the promise to them for good would turn to a cursing for them when they turned away from God.
Deuteronomy 30:10-20 (KJV) If thou shalt hearken unto the voice of the LORD thy God, to keep his commandments and his statutes which are written in this book of the law,
and if thou turn unto the LORD thy God with all thine heart, and with all thy soul. For this commandment which I command thee this day, it
is not hidden from thee, neither
is it far off. It
is not in heaven, that thou shouldest say, Who shall go up for us to heaven, and bring it unto us, that we may hear it, and do it? Neither
is it beyond the sea, that thou shouldest say, Who shall go over the sea for us, and bring it unto us, that we may hear it, and do it?
But the word is very nigh unto thee, in thy mouth, and in thy heart, that thou mayest do it. See, I have set before thee this day life and good, and death and evil; In that I command thee this day to love the LORD thy God, to walk in his ways, and to keep his commandments and his statutes and his judgments, that thou mayest live and multiply: and the LORD thy God shall bless thee in the land whither thou goest to possess it. But if thine heart turn away, so that thou wilt not hear, but shalt be drawn away, and worship other gods, and serve them; I denounce unto you this day, that ye shall surely perish, and that ye shall not prolong your days upon the land, whither thou passest over Jordan to go to possess it. I call heaven and earth to record this day against you,
that I have set before you life and death, blessing and cursing: therefore choose life, that both thou and thy seed may live: That thou mayest love the LORD thy God,
and that thou mayest obey his voice, and that thou mayest cleave unto him: for he
is thy life, and the length of thy days: that thou mayest dwell in the land which the LORD sware unto thy fathers, to Abraham, to Isaac, and to Jacob, to give them.
Joshua 23:2-16 (KJV) And Joshua called for all Israel,
and for their elders, and for their heads, and for their judges, and for their officers, and said unto them, I am old
and stricken in age:
And ye have seen all that the LORD your God hath done unto all these nations because of you; for the LORD your God is he that hath fought for you. Behold, I have divided unto you by lot these nations that remain, to be an inheritance for your tribes, from Jordan, with all the nations that I have cut off, even unto the great sea westward. And the LORD your God, he shall expel them from before you, and drive them from out of your sight; and ye shall possess their land, as the LORD your God hath promised unto you. Be ye therefore very courageous to keep and to do all that is written in the book of the law of Moses, that ye turn not aside therefrom
to the right hand or
to the left; That ye come not among these nations, these that remain among you; neither make mention of the name of their gods, nor cause to swear
by them, neither serve them, nor bow yourselves unto them:
But cleave unto the LORD your God, as ye have done unto this day. For the LORD hath driven out from before you great nations and strong: but as for you, no man hath been able to stand before you unto this day. One man of you shall chase a thousand: for the LORD your God, he it is that fighteth for you, as he hath promised you. Take good heed therefore unto yourselves, that ye love the LORD your God. Else if ye do in any wise go back, and cleave unto the remnant of these nations, even these that remain among you, and shall make marriages with them, and go in unto them, and they to you: Know for a certainty that the LORD your God will no more drive out any of these nations from before you; but they shall be snares and traps unto you, and scourges in your sides, and thorns in your eyes, until ye perish from off this good land which the LORD your God hath given you. And, behold, this day I
am going the way of all the earth: and
ye know in all your hearts and in all your souls, that not one thing hath failed of all the good things which the LORD your God spake concerning you; all are come to pass unto you, and not one thing hath failed thereof. Therefore it shall come to pass,
that as all good things are come upon you, which the LORD your God promised you; so shall the LORD bring upon you all evil things, until he have destroyed you from off this good land which the LORD your God hath given you. When ye have transgressed the covenant of the LORD your God, which he commanded you, and have gone and served other gods, and bowed yourselves to them; then shall the anger of the LORD be kindled against you, and ye shall perish quickly from off the good land which he hath given unto you.