Each religion differs to some degree. Catholic being considered the most strict, and the one I know about, I'll tell you this. You are married until annuled. You or your spouse cannot remarry in the eyes of the Church. Unfortunately, IMHO, the Church is much more liberal at granting annulments than it used to be. Divorce standing alone does not give you automatic freedom to remarry in the church. Staying single is an option, but not a requirement