Actually the popular heresy is the one mentioned above and historically much of what was spoken has been fulfilled through Jesus. The dispensational eschatology is a very new doctrine and many of the early church fathers did not teach this. However, that some how changed in the early 19th century? I don't see any biblical evidence that backs this teaching. Let's look at this from a more broader scope by going to the scriptures.

Let me first say God’s Love for all who believe however is not limited to the separation of world and the Church. We must trust God in everything we do and understand there is only one true way. We are the light and salt of the earth. What is the will of God? To love God and to love your neighbor. Nothing to divide over just my understanding, we all have the same ending.

26 For you are all sons of God through faith in Christ Jesus. 27 For as many of you as were baptized into Christ have put on Christ. 28 There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus. 29 And if you are Christ’s, then you are Abraham’s seed, and heirs according to the promise. Galatians 3:26-29

Jesus replied: “‘Love the Lord your God with all your heart and with all your soul and with all your mind.’ 38 This is the first and greatest commandment. 39 And the second is like it: ‘Love your neighbor as yourself.’ 40 All the Law and the Prophets hang on these two commandments.” Matthew 22:27-40

28 Then he said to them, “You know how unlawful it is for a Jewish man to keep company with or go to one of another nation. But God has shown me that I should not call any man common or unclean. Acts 10:28

Let's point to some of the new and old testament passages that do not exclude the command of God to love one another and love the stranger that is not apart of the community. There are various laws and passages the prove this point and thus giving us the broader picture of God’s plan for True Israel. Even though these passages look dimly towards the future from the OT writers, the new testament passages echo back to these very passages. Let's take a look at 1 Corinthians 13:13.

13 And now abide faith, hope, love, these three; but the greatest of these is love.

The greatest commandment is “ Love”. God displays that love throughout all generations, Deuteronomy 5:9 NKJV -- “For I, the Lord your God, am a jealous God, visiting the iniquity of the fathers upon the children to the third and fourth generations of those who hate Me, 10 but showing mercy to thousands, to those who love Me and keep My commandments.” This command extends to the each generation and to those who follow the true God of Israel, and not excluding foreigners who came to the faith. Even more passages point to God’s unfailing love to the outsider. Take a look at Leviticus 19:33-34 NIV

33 “‘When a foreigner resides among you in your land, do not mistreat them. 34 The foreigner residing among you must be treated as your native-born. Love them as yourself, for you were foreigners in Egypt. I am the Lord your God.

Deuteronomy 10
18 He administers justice for the fatherless and the widow, and loves the stranger, giving him food and clothing. 19 Therefore love the stranger, for you were strangers in the land of Egypt.

If this doesn't convince you, must we not take Ruth into consideration? Ruth was a Moabite, from a nation that worshiped idol gods. Ruth the Moabite and Rahab the prostitute was a Canaanite and are mention in the genealogy of Jesus Christ (Matt. 1:5).

Naomi speaking to Ruth after the death of her husband in Ruth 1:15
And she said, “Look, your sister-in-law has gone back to her people and to her gods; return after your sister-in-law.” 16 But Ruth said:

“Entreat me not to leave you,
Or to turn back from following after you;
For wherever you go, I will go;
And wherever you lodge, I will lodge;
Your people shall be my people,
And your God, my God.
17 Where you die, I will die,
And there will I be buried.
The Lord do so to me, and more also,
If anything but death parts you and me.”

Another example how God’s unfailing love is displayed through Boaz, Ruth's redeemer and husband , a type of Christ that bridges the gap from Jew to Gentile and extends his arm to the Moabite in Ruth 2. God has always made a way and still does. He never changes and is forever loving across all generations, the creator of all men, from one man he made all the nations, that they should inhabit the whole earth; and he marked out their appointed times in history and the boundaries of their lands (Acts 17:26).

Esther was a Jewish queen of the Persian king Ahasuerus to read this you see the magnificent work of God and His love for the people and one missed thing, His love for those who converted.
Esther 8:17 “
And in every province and city, wherever the king’s command and decree came, the Jews had joy and gladness, a feast and a holiday. Then many of the people of the land became Jews, because fear of the Jews fell upon them.”

Did the people of the land somehow change their genealogy and become Jews? Some would argue the dispensation ideology that is weakling defended in Ephesians 3, but yet leave out the meaning and purpose of what Paul was saying.

Sure we are in the age of the Church, and the end of the age of sacrifices, and Israel is his inheritance. First to the Jew then to the Gentiles, however this never excluded those who wanted to take part of the covenant community. If that were not true then why were those who were unbelievers circumcised once they converted? However God also called even Egypt His people.

Isaiah 19:24-25
24 In that day Israel will be one of three with Egypt and Assyria—a blessing in the midst of the land, 25 whom the Lord of hosts shall bless, saying, “Blessed is Egypt My people, and Assyria the work of My hands, and Israel My inheritance.”

Much more can be said but on one final note. Regardless the argument between Jew and Gentile the whole purpose of Christ was to bridge that gap once and for all. So even if God were to have two separate people with two separate plans I will revert back always to Galatians 3:28 every time. The Zionist movement and ideology has done more harm to the middle east then most would like to admit. If you disagree with these people and reject the propagated notion of the 19th century dispensationalism you will be demonized. Words of John: Yet to all who did receive him, to those who believed in his name, he gave the right to become children of God— children born not of natural descent, nor of human decision or a husband’s will, but born of God.

Matt. 21:43-46 - ( in reference to Zechariah 12)
43 “Therefore I say to you, the kingdom of God will be taken from you and given to a nation bearing the fruits of it. 44 And whoever falls on this stone will be broken; but on whomever it falls, it will grind him to powder.”

45 Now when the chief priests and Pharisees heard His parables, they perceived that He was speaking of them. 46 But when they sought to lay hands on Him, they feared the multitudes, because they took Him for a prophet.

I will never demonize those who hold another view on this. I love all no matter who you are. Christ died for all.

PS. More scripture for your reading.
Rom. 11:11-24
Ezek. 11:17-17-20
Amos 9:9-12
Ephesians 2:14-18
Romans 3:9-18
Romans 3:28:29
Romans 10:12-13
Ephesians 3:3-7
Isaiah 54:5-8
1 Timothy 1:3-4
Who is virgin Israel? Jeremiah 31:2-7 Read 2 Corinthians 11:2-3
Jeremiah 31:31-34
Titus 3:9-11

Thanks for the comment and God bless.