1. Those who believe in Jesus as the Christ are true circumcision and true Jews. (Phil 3:3)
    Col 2:11, Rom 2:29, Jn 4:24, Rom 7:6

Phil 3:3 For we are the circumcision, which worship God in the spirit, and rejoice in Christ Jesus, and have no confidence in the flesh.

We have been circumcised by Christ by believing that Jesus is the Christ. That is, the Holy Spirit has come into our hearts. (Col 2:11, Rom 2:29)

Col 2:11 In whom also ye are circumcised with the circumcision made without hands, in putting off the body of the sins of the flesh by the circumcision of Christ:

Rom 2:29 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.

Now we worship God with the Holy Spirit, not the Law. (Rom 7:6, Jn 4:24)

Rom 7:6 But now we are delivered from the law, that being dead wherein we were held; that we should serve in newness of spirit, and not in the oldness of the letter.

Jn 4:24 God is a Spirit: and they that worship him must worship him in spirit and in truth.