Adam Clarke on Philippians 3:18

For many walk, etc - The Judaizing teachers continue to preach, who wish to incorporate circumcision, and other ordinances of the law, with the Gospel.

They are the enemies of the cross of Christ - They rather attribute justification to the Levitical sacrifices, than to the sacrificial death of Christ; and thus they are enemies to that cross, and will not suffer persecution for its sake. They please the world, and are in no danger of reproach.