I don't believe this is true. There is no 'physical birth into God's people'. What is 'flesh is flesh' and what is 'spirit is spirit'. Circumcision was the 'mark of entry' into the Covenant of God. It was not simply 'a sign' of membership of the 'people of God' as you appear to assert in your reply. No people are simply 'born into God's people' they are brought into God's Covenant on their own volition (God-Fears) or through the will of their parents (those children whose parents are already in the Covenant). This was a telling post though as to the differences between you and I in this regard and I am thankful for it because I understand better the differences we have.
And yet it is manifestly so. For a Jew is either born a Jew or he is not. Is circumcision important? Yes. Even necessarry. May other convert to the religion of the Jews? Indeed. But may those ocnverts be rightly said to descendand from Israel or it's tribes? No. My point is imply that a Jew born is born into the people of God as well as circumcised. The two are inseperably united in thge purpose of God for those born of Abraham through Israel.
You forget: when Abraham circumcised, he circumcized his household (ah, yes, that term again). I hope Genesis 17:23-7 is clear enough for you. And I hope Genesis 17:12-3 is abudantly clear. Hence the reason why the Judaizers were insisting on circumcision of Gentile converts.
Likewise, those born of Abraham by faith through Christ are also united without an outward sign or token of the covenant communitty for which they were born to partake.
And those Hebrew also MUST be baptized who born of Abraham of faith as well as the flesh. (Like yours truly
That said, though I have for the sake of conversation permitted myself to draw form the circumcision analogy with baptism, and though not denying some merit to that application, I must clarify that I do not believe baptism to be the inward circumcision of which the NT speaks. It is the heart that is circumcised under the NT, the inner spiritual man. Here again I believe baptism to be a witness to this inner reality or experience -- but not the fulfillment thereof itself.
Colossians 2:4 τοῦτο λέγω, ἵνα μηδεὶς ὑμᾶς παραλογίζηται ἐν πιθανολογίᾳ.
Now this I say that no one may delude you with persuasiveness of speech.
Colossians 2:5 εἰ γὰρ καὶ τῇ σαρκὶ ἄπειμι, ἀλλὰ τῷ πνεύματι σὺν ὑμῖν εἰμι, χαίρων καὶ βλέπων ὑμῶν τὴν τάξιν καὶ τὸ στερέωμα τῆς εἰς Χριστὸν πίστεως ὑμῶν.
For though I am absent in the flesh, yet am I with you in the spirit, rejoicing and seeing your order, and the steadfastness of your faith in Christ.
Colossians 2:6 ὡς οὖν παρελάβετε τὸν Χριστὸν Ἰησοῦν τὸν κύριον, ἐν αὐτῷ περιπατεῖτε,
As therefore you received Christ Jesus, the Lord, walk in him,
Colossians 2:7 ἐρριζωμένοι καὶ ἐποικοδομούμενοι ἐν αὐτῷ καὶ βεβαιούμενοι τῇ πίστει καθὼς ἐδιδάχθητε, περισσεύοντες (ἐν) (αὐτῇ) ἐν εὐχαριστίᾳ.
rooted and built up in him, and established in the faith, even as you were taught, abounding in it in thanksgiving.
Colossians 2:8 βλέπετε μή τις ὑμᾶς ἔσται ὁ συλαγωγῶν διὰ τῆς φιλοσοφίας καὶ κενῆς ἀπάτης κατὰ τὴν παράδοσιν τῶν ἀνθρώπων κατὰ τὰ στοιχεῖα τοῦ κόσμου καὶ οὐ κατὰ Χριστόν·
Be careful that you don't let anyone rob you through his philosophy and vain deceit, after the tradition of men, after the elements of the world, and not after Christ
Colossians 2:9 ὅτι ἐν αὐτῷ κατοικεῖ πᾶν τὸ πλήρωμα τῆς θεότητος σωματικῶς,
For in him all the fullness of the Godhead dwells bodily,
Colossians 2:10 καὶ ἐστὲ ἐν αὐτῷ πεπληρωμένοι, ὅς ἐστιν ἡ κεφαλὴ πάσης ἀρχῆς καὶ ἐξουσίας.
and in him you are made full, who is the head of all principality and power;
Colossians 2:11 ἐν ᾧ καὶ περιετμήθητε περιτομῇ ἀχειροποιήτῳ ἐν τῇ ἀπεκδύσει τοῦ σώματος τῆς σαρκός, ἐν τῇ περιτομῇ τοῦ Χριστοῦ,
in whom you were also circumcised with a circumcision not made with hands, in the putting off of the body of the sins of the flesh, in the circumcision of Christ;
Colossians 2:12 συνταφέντες αὐτῷ ἐν τῷ βαπτίσματι / βαπτισμῷ, ἐν ᾧ καὶ συνηγέρθητε διὰ τῆς πίστεως τῆς ἐνεργείας τοῦ θεοῦ τοῦ ἐγείραντος αὐτὸν ἐκ νεκρῶν· having been buried with him in baptism
, in which you were also raised with him through faith in the working of God, who raised him from the dead
Colossians 2:13 καὶ ὑμᾶς νεκροὺς ὄντας [ἐν] τοῖς παραπτώμασιν καὶ τῇ ἀκροβυστίᾳ τῆς σαρκὸς ὑμῶν συνεζωοποίησεν ὑμᾶς σὺν αὐτῷ, χαρισάμενος ἡμῖν πάντα τὰ παραπτώματα.
You were dead through your trespasses and the uncircumcision of your flesh. He made you alive together with him, having forgiven us all our trespasses,
Colossians 2:14 ἐξαλείψας τὸ καθ' ἡμῶν χειρόγραφον τοῖς δόγμασιν ὃ ἦν ὑπεναντίον ἡμῖν καὶ αὐτὸ ἦρκεν ἐκ τοῦ μέσου προσηλώσας αὐτὸ τῷ σταυρῷ·
wiping out the handwriting in ordinances which was against us; and he has taken it out of the way, nailing it to the cross;
Colossians 2:15 ἀπεκδυσάμενος τὰς ἀρχὰς καὶ τὰς ἐξουσίας ἐδειγμάτισεν ἐν παρρησίᾳ θριαμβεύσας αὐτοὺς ἐν αὐτῷ.
having stripped the principalities and the powers, he made a show of them openly, triumphing over them in it.
Colossians 2:16 Μὴ οὖν τις ὑμᾶς κρινέτω ἐν βρώσει καὶ ἐν πόσει ἢ ἐν μέρει ἑορτῆς ἢ νεομηνίας ἢ σαββάτων·
Let no one therefore judge you in eating, or in drinking, or with respect to a feast day or a new moon or a Sabbath day,
Colossians 2:17 ἅ ἐστιν σκιὰ τῶν μελλόντων, τὸ δὲ σῶμα τοῦ Χριστοῦ.
which are a shadow of the things to come; but the body is Christ's.
How much plainer can it be? in the circumcision of Christ having been buried with him in baptism
From sun and thapto; to inter in company with, i.e. (figuratively) to assimilate spiritually (to Christ by a sepulture as to sin) -- bury with.
The only other occurence in the NT is
Romans 6:4 συνετάφημεν οὖν αὐτῷ διὰ τοῦ βαπτίσματος εἰς τὸν θάνατον, ἵνα ὥσπερ ἠγέρθη Χριστὸς ἐκ νεκρῶν διὰ τῆς δόξης τοῦ πατρός, οὕτως καὶ ἡμεῖς ἐν καινότητι ζωῆς περιπατήσωμεν.
We were buried therefore with him through baptism to death, that just like Christ was raised from the dead through the glory of the Father, so we also
might walk in newness of life.
with all the implications (which no doubt I and the Apostles' Church disagree with you on) of that chapter on baptism and its effects.
We were buried:cause
so we also might walk: effect (btw, notice "might," not "shall").
The fact that the aorist is used emphasis the puntual nature of the action: it was done in an act at a certain point of time (say, at BAPTISM).