The natural condition of a male, with the foreskin covering his penis. The Jewish people, along with many other groups, surgically removed this foreskin as a sign of their covenant (agreement) with God (Genesis 17:9–14; Exodus 12:48; Leviticus 12:3). Because of this practice, the term "uncircumcision" came to mean "non-Jew" or "gentile" (Philistines, Greeks, and Romans did not practice circumcision, but Egyptians and many Semitic peoples did). The word was also used to describe "those outside the covenant."
The term “uncircumcision” occurs 20 times in the New Testament, usually simply meaning "gentile," as opposed to Jew. Paul presents a compelling case against making such distinctions. Paul strongly argues against making such distinctions between people. For Paul, the attitude of a person's heart toward God is much more important than following ritual law, which has nothing to do with a person's salvation (Romans 2:25–27). Abraham became a believer and was accepted by God while he was still uncircumcised. So circumcision has nothing to do with his salvation (Romans 3:30; 4:9–12). In the past, gentiles were excluded from being God's people (Ephesians 2:11–12). Now, Jewish and gentile believers have become one people in Jesus Christ (Galatians 2:7; 5:6; 6:15; Colossians 3:11). Paul refuses to listen to those requiring circumcision for full church membership.
In Colossians 2:8–15, Paul uses "uncircumcision" as a metaphor, meaning a person's state before knowing God. Here uncircumcision equals "the flesh" (meaning one's evil desires). It is the same as being uncircumcised. Just as physical flesh is cut away during circumcision, this spiritual "flesh" is cut away by Christ at the time of conversion, as shown in baptism. The baptized person is cleansed from "uncleanness" just as a circumcised gentile was considered cleansed from previous uncircumcised uncleanness.