What is the Abrahamic covenant mentioned in Genesis 17:7, 17:13 and 17:19? What aspect of the Abrahamic covenant is everlasting? Why don’t Christians practice circumcision if the Abrahamic covenant is everlasting?
I wish that this was a simple question with a simple answer. One difficulty here is that the Jewish concept of the Hebrew word translated as “everlasting” is not what we in the Western world would think. The Hebrew word is olam. For us everlasting means forever, which means for a theoretically infinite amount of time. But the word olam does not necessarily carry that meaning, which is why it is difficult to translate. It is translated as ancient, from of old, lasting, everlasting, forever, long ago, always, old, age-old and more. The generic meaning of olam is for a great period of time, or until the present age comes to an end. For example, the Covenant of Moses was olam, but it was completed by Jesus (Matthew 5:17) and is no longer in force. The covenant with Abraham was in place until the end of the age that God had in mind for it to be in place, which could literally be the English meaning of eternal or not.
Then it gets even more complicated. For example, is circumcision even part of this covenant in Genesis 17? It is not mentioned. Paul mentions in Romans 4 that Paul was credited for his righteousness before he was circumcised. In fact, the basic covenant of Genesis 17 was given to Abraham in Genesis 12:1-2, which was certainly before he was circumcised. To me, that means that circumcision is not necessarily a part of the covenant with Abraham at all.
But that is not the only complication. Some of the promises to Abraham in Genesis 12, Genesis 15, Genesis 17 and Genesis 22 have to do with things about the Jewish people only, and other parts of the promise are for all people, including non-Jews, including us. For example, God made nations from Abraham (Edom, Arabs, Jews). Kings came from Abraham. These are about the past. God gave the land of Canaan to Abraham’s descendents–the Jews. That, too, is a thing of the past, which has since ended. But then, there are promises that still apply today, such as Genesis 12:3. All nations will be blessed. This is fulfilled in Jesus.
We do not practice circumcision because God made it clear to the apostles that we do not practice circumcision. This was for the Jews alone.