The circumcision has great significance. This activity means a person will not live for the sinful desire.
The person will desire to follow the Lord. It is an outward thing for the desire of the person heart.
If a person does an activity for God but don't have a new heart. Then that person can't please the Lord.
The person needs a pure heart. The human heart is sinful.
Jesus came to this world and died on the cross. When a person repent from their sins then the Holy Spirit seals the believer. The believer's heart will receive a new heart. The new heart will hate sin and love the law of the Lord.