Galatians 6:13

‘FOR THOSE WHO RECEIVE CIRCUMCISION DO NOT EVEN THEMSELVES KEEP THE LAW. BUT THEY DESIRE TO HAVE YOU CIRCUMCISED THAT THEY MAY GLORY IN YOUR FLESH.'

Let them consider the second fact. That those who try to bring them in subjection to the Law cannot even keep the Law themselves. They offer them something that they themselves are unable to achieve. And they do it simply so that they can glory in what they achieve by having them circumcised. Indeed they want to ‘glory in your flesh'. In other words their glory is not in Christ but in fleshly things, they glory in ordinances, they glory especially in making men undergo circumcision that they may say, ‘see, he is marked as one of ours'. They are of those who follow the pull of the flesh, and they want others to be the same. They are not responsive to the Spirit, and they want them to behave likewise. For to be circumcised for this reason is as fleshly as all the other works of the flesh.

So those who want them to be circumcised and submit to ritual ordinances do it simply because they want to have physical proof of their success. They want to be able to glory in it. ‘See', they want to be able to say, ‘they have submitted to circumcision'. Then they will receive their congratulations, and there it will end. The desires of their flesh will be satisfied.