Why christians are not circumcised , and Jesus was?

Jews are born under the Abrahamic Covenant. As an outward sign that they are covenant people, they are circumcised. Jesus brought the New and Everlasting Covenant. Those bound by this are not required to be circumcised. Instead of an animal sacrifice, they must offer a broken spirit and a contrite heart.

Jesus did all that a devout Jew is required to do.

Jesus did not give permission for his circumcision. He was circumcised when he was 8 days old.

The mission of Jesus is to teach people about God, God's kingdom and about the way to God's kingdom. Jesus taught that the only way to God's kingdom is by joining hands with God and doing what God wants us to do here on earth. Circumcision does not help.

Because Jesus, being an Israelite, lived under the Law given to Moses, thus was circumcised, as was every other man/boy.

After JC died, Christianity was practiced by his followers who recognized that 'Jesus fulfilled the law given to Moses'.

Jesus didn't pass on the requirement to be circumcised, he taught that the principle of Love, properly appreciated, will guide one in all areas of life, and no huge body of rules & regulations was any longer required.

Works are not required for salvation, see Eph 2:8-9

many Western Christians are circumcised

the bulk of US American males are circumcised

yet Christians are not bound to that jewish custom

Uhh, I am circumcized just like most Christians are.

There are actually health benefits as well. It keeps "the area" cleaner down there and less open to infections.

Jesus was Jewish.

There are still some Jews who perform circumcision with their mouths. TRUE.

Belief has nothing to do with circumcision.

My son is for hygiene reasons, and it's the norm here in the USA.

Many are. It is a very personal decision, some even call it mutilation....