Ecclesiastical corporations. Any number of persons, not less than 3, may incorporate for the purpose of establishing any church organization for the purpose of teaching and spreading their religious beliefs and principles. Every such corporation shall be a non-profit corporation and subject to the provisions of this act relating to non-profit corporations generally except as specifically otherwise provided. The term “church” and/or “church organization” used in this act shall be construed to include any church, denominational unit, or church society as the term is commonly used and understood but shall not apply to such organizations as Sunday schools, Epworth Leagues, Young People’s Unions, Bible classes and similar societies organized by and affiliated with the parent churches. Whenever any number of churches or other corporations organized for religious purposes desire to unite in a central organization for the accomplishment of any common purpose they may incorporate such organization by severally adopting, at meetings specially called for the purpose, resolutions expressing their desire to become members of such corporation; and by filing duly attested copies of such resolutions together with a copy of the articles of such corporation, as provided for the filing of articles in section 5 of this act. The corporations formed under this section are hereinafter called ecclesiastical corporations.