Judaism has had circumcision as a part of its religious practices for many years. It is done in a ceremony that includes family and friends. Not allowing this practice is an oppression of the religion. The procedure is a personal choice for the family and not something that the national government should be banning.
In Judaism, Islam, and specific Orthodox Churches circumcision is a religious ritual. Banning circumcision in Denmark would mean that those who practice these religions would no longer be able circumcise their sons. If circumcision is banned, there should be an allowance for those who want to perform a circumcision based on their religious views.
I agree with those who believe there is no good reason to perform a circumcision. I have read the research and see that there really aren't any direct health benefits to circumcision. However, there really aren't any drawbacks, either. I think that if a person chooses to have their son circumcised, whether for religious reasons or personal preference, the government shouldn't be allowed to stop them.
Religious freedom is necessarily limited to that which an individual decides to do with their own self- as such, religious freedom enures Jews and Muslims the right to be circumcised, but in no way does it give them any right to circumcise someone else without their consent. To borrow a line from the French Declaration of the rights of man: "Liberty consists in the freedom to do everything which injures no one else," as such circumcising your child is not a valid form of religious freedom or freedom of expression.
All the research done in Denmark in recent times show it is a very secular country in which church attendance is very low. Overall Denmark, much like other countries that have very low religiosity levels, is a very happy and stable country. Any action by the Government to further cement that makes sense. Plus the people that want it would still be able to go to another country and have it done, they won't go to prison for it.