Divorce is a final and irrevocable act of separating from your spouse. There are other forms of separation that are not as final.
If there has been a valid marriage you can file for a divorce. However, if the validity of your marriage is in question then you still have to approach the Court to separate legally through separation by annulment.
Approach a Court
You have to go to Court to file a divorce case. While the divorce case is going on, you will continue to have certain duties towards your spouse and children such as giving financial support to them.