Here Acts 15:1 will be explained to show how believers are deemed ‘saved’ before they are circumcised, and that the verse in no way abolishes the commandment of circumcision.
At the time, some dear zealous Pharisees who believed that Christ was Messiah, sadly incorrectly still thought it was the circumcision which meant a person was ‘saved’ and resulted in the conversion of a person.
For reference, even still today conversion in traditional Judaism (those who do not yet believe in Messiah), takes place after the circumcision.
With this, believers are further instructed not to force other believers to be circumcised. They will however, naturally seek and desire to be circumcised as they come to the knowledge of the commandment – as this means they are trying to uphold the Law of Moses with their faith.