Any number of persons, not less than twenty, a majority of whom must be bona fide residents of this state, may become, together with others who thereafter may be associated with them or their successors, a body corporate for the purpose of carrying on the business of mutual insurance as provided in this chapter by complying with this chapter. Any number of persons, not less than seven, may form a mutual life insurance company and, with others who may become associated with them or their successors, may become a body corporate for the purpose of carrying on the business of a mutual life insurance company. A mutual life insurance company organized under this chapter may carry insurance upon the lives of persons, including every kind of insurance pertaining thereto.