The natural Jews and Jewish proselytes were given the first opportunity to be chosen for spiritual Israel, only a minority of that nation responded. God, therefore, extended the invitation to the Gentiles.
The opportunity was first given to the Jews, and Jewish proselytes because God made a covenant with their forefathers, saying to Abraham. Read Genesis 26:2-4
Acts 3:25-26 NASB
25 It is you who are the sons of the prophets and of the covenant
which God made with your fathers, saying to Abraham, ‘And in your seed
all the families of the earth shall be blessed.’ 26 For you first, God
raised up His Servant and sent Him to bless you by turning every one
of you from your wicked ways.”
Only a small number of Israelites obviously accepted the invitation, God, therefore, extended the invitation to the gentiles, Cornelius being the first noncircumcised person to become a Christian.
Acts 18:5-6 NASB
5 But when Silas and Timothy came down from Macedonia, Paul began
devoting himself completely to the word, solemnly testifying to the
Jews that Jesus was the [a]Christ. 6 But when they resisted and
blasphemed, he shook out his garments and said to them, “Your blood be
on your own heads! I am clean. From now on I will go to the Gentiles.”
John 1:10-13 NASB
10 He was in the world, and the world was made through Him, and the
world did not know Him. 11 He came to His own, and those who were
His own did not receive Him. 12 But as many as received Him, to them
He gave the right to become children of God, even to those who believe
in His name, 13 who were [b]born, not of [c]blood nor of the will of
the flesh nor of the will of man, but of God.
The Parable of the Marriage Feast. Matthew 22:1-14
The Parable refers to the above invitation, recommend reading.
First Invitation to the Jews.
Jesus introduces his illustration by mentioning "the Kingdom of the heavens." Logically, then, the "king" must be God. The KIng give a wedding feast for His Son, the son is Jesus. The first ones to be invited were the Jews, for three and a half years Jesus and the apostles were preaching about the Kingdom.
And how did most Israelites respond to the invitation? As Jesus said, "they were unwilling to come." The majority of the religious leaders and the people did not accept the invitation. (read Vs 3)
Second invitation to the Jews ,
Despite the poor response, Jesus gives the Jews a second opportunity, the preaching of the Kingdom news continues by the apostles and others exclusively to the Jews. (Matthew 22:4-6)
With what outcome for the nation? Jesus relates: " But the king was enraged, and he sent his armies and destroyed those murderers and set their city on fire. (Matthew 22:7) The Jews experienced that in 70 C.E. when the Romans destroyed the city -"Jerusalem."
Again the Jews refuse the kings invitation and so the king says to his slaves (The slaves are the apostles and othes like Paul, Luke, Timothy, and Stephen)
The Invitation is now extended to the Gentiles.
Then he *said to his slaves, ‘The wedding is ready, but those who were
invited were not worthy. 9 Go therefore to the main highways, and as
many as you find there, invite to the wedding feast.’ 10 Those slaves
went out into the streets and gathered together all they found, both
evil and good; and the wedding hall was filled with [e]dinner guests.
The apostle Peter would later begin helping Gentiles "Non-Jews." In 36 C.E., The Roman army officer Cornelius and his family received God’s spirit, coming in line for a place in the Kingdom of the heavens that Jesus mentioned. Acts 10:1, 34-48.