Any corporation organized to insure lives, which provides for the payment of policy claims, the accumulation of reserve or emergency funds, and the expense of the management and prosecution of the business by payments to be made either at periods named in the contract or upon assessment as required, by persons holding similar contracts, and wherein the insured’s liability to contribute to the payment of policy claims accrued or to accrue is not limited to a fixed sum, shall be deemed to be engaged in the business of life insurance upon the assessment plan, and be subject only to the provisions of this article. This article shall not apply to secret or fraternal societies conducting their business on the lodge system, or to associations organized solely for benevolent or charitable purposes, and which are now permitted by law to do business in this state.