1964 KM - Page 4:
Question Box: What viewpoint should we take toward membership in such organizations as the YMCA, if one's membership is solely for the use of recreational facilities?
Answer: The Young Men's Christian Association is in actuality a manifestation of interfaith. Regardless of the reasons for which various persons may personally choose to be affiliated with it, the underlying purpose of the organization itself is religious. One who fills out a membership form and pays the required fee so that he will be entitled to regular use of the organization's recreational facilities becomes a part of that organization. And it must be borne in mind that all these religious systems that are not serving Jehovah God are part of Babylon the Great. Joining such an organization is an act of apostasy. How unwise it would be to assign bodily exercise such a prominent place in our lives that we would compromise our faith to engage in it! (1 Tim. 4:8) So if any have done this without realizing what was involved, it would be wise to take action right away to sever those connections.
Of course, it ought to be borne in mind that becoming a card-carrying member of an organization such as this is different from renting their facilities on a particular occasion for a stipulated price. On occasion, auditoriums and swimming pools have been rented from these organizations for use in connection with an assembly, but that is not the same as entering into an alliance with the organization as a member of it.