Many Christians think of themselves as the "chosen" which is a misnomer. Christians, who are born again believers, are the "called" which I will prove to you with the Scriptures.
First lets go to the Lexical Aid and define the Greek and Hebrew words "chosen" and "called."
To start with the word "called" in the Greek Strong's Concordance # 1577 Ekklesia; originally seems to have been derived from ekkaleo, to call out. It was a common term for a congregation of the ekkletol, those called out or assembled in the public affairs of a free state; a body of free citizens called together by a herald (kerux #2783). The ekkletoi, the called people, constituted the ekklesia. The Christian community was designated for the first time as ekklesia to differentiate it from the Jewish community, sunagoge (Acts 2:47).
The term ekklesia denotes the New Testament community of the redeemed in its twofold aspect; all who are called by and to Christ in the fellowship of His salvation, the Church worldwide (of born again believers who practice the WORD of God) of all times.
Now to the word "chosen." Strong's #1588 Ekklektos: in described in the Greek Lexical Aid as Eklektos: chosen, election (Matthew 20:16; Luke 18:7) which is related to eklegomai (1586) to choose. In the Old Testament Strong's # 977 in Hebrew: has chosen - Bachar; to prove, try, choose, select, distinguish, love, like, to be pleasing, to be especially chosen. Something is acceptable or judged to be excellent after it has been tested. In other words it is considered to be the best.
We all know that Israel failed miserably when God tried to test the Jews. Grace was instituted for that reason which came through Jesus Christ.
You will not find the word "chosen" in conjunction with Gentiles, that is why the Scriptures state: "So the last shall be first, and the first last: for many be called, but few chosen. (Matthew 20:16)
Many are called, but few are chosen. Israel compared to the world are few. Notice while we are at it: this is a Rapture Scripture: "the last shall be first (the called) and the first last (the chosen)." The Jews were delt with first and the called came later in the New Testament.
The Old Testment addresses the Jews. God speaking to Jacob: "But thou, Israel, [art] my servant, Jacob whom I have chosen, the seed of Abraham my friend. [Thou] whom I have taken from the ends of the earth, and called thee from the chief men thereof, and said unto thee, Thou [art] my servant; I have chosen thee, and not cast thee away." (Isaiah 41:8,9)
"For thou [art] an holy people unto the LORD thy God: the LORD thy God hath chosen thee to be a special people unto himself, above all people that [are] upon the face of the earth. (Deuteronomy 7:6) "For thou [art] an holy people unto the LORD thy God, and the LORD hath chosen thee to be a peculiar people unto himself, above all the nations that [are] upon the earth." (Deuteronomy 14:2) "O ye seed of Israel his servant, ye children of Jacob, his chosen ones. (1 Chronicles 16:13)
The word chosen ones comes into play when Jesus chose the Apostles who were Jews including Apostle Paul.
It comes up in the New Testament in Romans 16:13 where Rufus whose father carried the cross to the hill, was considered chosen and we find in Col 4:11 "And Jesus, which is called Justus, who are of the circumcision. These only [are my] fellowworkers unto the kingdom of God, which have been a comfort unto me..." that he was a Jew who had converted to Christ.
The word "chosen" comes up in James 2:5
"Hearken, my beloved brethren, Hath not God chosen the poor of this world rich in faith, and heirs of the kingdom which he hath promised to them that love him? (James 2:5)
This particular word "chosen" is not considered to be the same as the "chosen" which relates to the Jews.
Strong's # 1586 Eklegomai; voice of eklego, from ek (1537) out, and lego (3004). To speak intelligently. Keeping in view a relation to be established between him and the object.
The following verses refer to the Jews who were disobedient and have become obedient under the leadership of Christ Jesus.
"But ye [are] a chosen generation, a royal priesthood, an holy nation, a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light: Which in time past [were] not a people, but [are] now the people of God: which had not obtained mercy, but now have obtained mercy. (1 Peter 2:9,10)
NOW TO THE CHURCH (the Body of Christ).
"And he "called" the multitude, and said unto them, Hear, and understand: (Matthew 15:10) "But he answered and said, Every plant, which my heavenly Father hath not planted, shall be rooted up. Let them alone: they be blind leaders of the blind. And if the blind lead the blind, both shall fall into the ditch. (Matthew 15:13,14) How does the Father plant? By the Word of God.
"And straightway he "called" them: and they left their father Zebedee in the ship with the hired servants, and went after him. (Mark 1:20)
"After this I will return, and will build again the tabernacle of David, which is fallen down; and I will build again the ruins thereof, and I will set it up: (Acts 15:16) "That the residue of men might seek after the Lord, and all the Gentiles, upon whom my name is "called," saith the Lord, who doeth all these things. (Acts 15:17)
"Paul, a servant of Jesus Christ, "called" [to be] an apostle, separated unto the gospel of God, (Romans 1:1) "Moreover whom he did predestinate, them he also "called:" and whom he "called," them he also justified: and whom he justified, them he also glorified. (Romans 8:30)
"Even us, whom he hath "called," not of the Jews only, but also of the Gentiles? (Romans 9:24)
"Unto the church of God which is at Corinth, to them that are sanctified in Christ Jesus, "called" [to be] saints, with all that in every place call upon the name of Jesus Christ our Lord, both theirs and ours: (1 Corinthians 1:2)
"God [is] faithful, by whom ye were "called" unto the fellowship of his Son Jesus Christ our Lord. (1 Corinthians 1:9) "But unto them which are "called," both Jews and Greeks, Christ the power of God, and the wisdom of God. (1 Corinthians 1:24)
"And let the peace of God rule in your hearts, to the which also ye are "called" in one body; and be ye thankful. (Colossians 3:15) "Who hath saved us, and "called" [us] with an holy calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before the world began, (2 Timothy 1:9)
"Jude, the servant of Jesus Christ, and brother of James, to them that are sanctified by God the Father, and preserved in Jesus Christ, [and] "called:" (Jude 1:1)
"These shall make war with the Lamb, and the Lamb shall overcome them: for he is Lord of lords, and King of kings: and they that are with him [are] "called," and "chosen," and faithful. (Revelation 17:14) Here He points out that the "chosen" Israel (the remnant) will be redeemed in spite of themselves. The "called" is the church, the "chosen" is Israel and all will be the faithful. They will have God's heart.
"And he saith unto me, Write, Blessed [are] they which are "called" unto the marriage supper of the Lamb. And he saith unto me, These are the true sayings of God. (Revelation 19:9)