Before any such mutual company shall solicit initial applications for insurance or sell certificates of indebtedness, it shall file with the commissioner of insurance a certified copy of its charter, bylaws, policy forms, and application therefor and rates covering all classifications of insurance to be written and a copy of the certificate of indebtedness to be issued, and receive written approval of all documents filed and written authorization from the commissioner of insurance for the solicitation of application and the sale of certificates of indebtedness.