"For in Christ Jesus neither circumcision availeth any thing, nor uncircumcision, but a new creature."
Galatians 6:15, KJV
"Lie not one to another, seeing that ye have put off the old man with his deeds; And have put on the new man, which is renewed in knowledge after the image of him that created him: Where there is neither Greek nor Jew, circumcision nor uncircumcision, Barbarian, Scythian, bond nor free: but Christ is all, and in all."
Colossians 3:9-11, KJV
"For he is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh: But he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God."
Romans 2:28-29, KJV
"Holding fast the faithful word as he hath been taught, that he may be able by sound doctrine both to exhort and to convince the gainsayers. For there are many unruly and vain talkers and deceivers, specially they of the circumcision: Whose mouths must be stopped, who subvert whole houses, teaching things which they ought not, for filthy lucre's sake."
Titus 1:9-11, KJV
"O foolish Galatians, who hath bewitched you, that ye should not obey the truth, before whose eyes Jesus Christ hath been evidently set forth, crucified among you? This only would I learn of you, Received ye the Spirit by the works of the law, or by the hearing of faith? Are ye so foolish? having begun in the Spirit, are ye now made perfect by the flesh? Have ye suffered so many things in vain? if it be yet in vain."
Galatians 3:1-4, KJV
"And the apostles and brethren that were in Judaea heard that the Gentiles had also received the word of God. And when Peter was come up to Jerusalem, they that were of the circumcision contended with him, Saying, Thou wentest in to men uncircumcised, and didst eat with them."
Acts 11:1-3, KJV
"Now therefore why tempt ye God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear? But we believe that through the grace of the Lord Jesus Christ we shall be saved, even as they."
Acts 15:10-11, KJV
The Biblical conclusion, regarding circumcision, or any other physical act to try to save ourselves, is simply this: They are all self-righteous works which do us absolutely no good whatsoever insofar as our Salvation is concerned :
"For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast."
Ephesians 2:8-9, KJV
"Wherefore, my brethren, ye also are become dead to the law by the body of Christ; that ye should be married to another, even to him who is raised from the dead, that we should bring forth fruit unto God."
Romans 7:4, KJV