Since there is only one God, who will justify the circumcised by faith and the uncircumcised through that same faith. (NIV)
Since it is one and the same God Who will justify the circumcised by faith [which germinated from Abraham] and the uncircumcised through their [newly acquired] faith. [For it is the same trusting faith in both cases, a firmly relying faith in Jesus Christ]. (AMP)
Seeing it is one God, which shall justify the circumcision by faith, and uncircumcision through faith. (KJV)